Truth” is revisiting a painful chapter for CBS News. The upcoming movie, starring Cate Blanchett as producer Mary Mapes and Robert Redford as Dan Rather, is an unwelcome reminder of past mistakes for several people who lived through the saga of the 2004 “60 Minutes II” report on President George W. Bush’s time in the Texas Air National Guard.

Some who are depicted in the controversial film, which is based on Mapes’ 2005 book “Truth and Duty: The Press, the President and the Privilege of Power,” are critical of the conclusions drawn by the veteran investigative journalist.

They were hopeful that the picture, which debuts in theaters on Oct. 16, would come and go quickly in limited release. But Blanchett is generating Oscar buzz as a best actress contender for her tour de force performance as the hard-charging producer swept up in a firestorm of partisan politics and media scrutiny of her work.

“It’s astounding how little truth there is in ‘Truth,’” a CBS spokesman said in response to Variety’s inquiry. “There are, in fact, too many distortions, evasions and baseless conspiracy theories to enumerate them all. The film tries to turn gross errors of journalism and judgment into acts of heroism and martyrdom. That’s a disservice not just to the public but to journalists across the world who go out every day and do everything within their power, sometimes at great risk to themselves, to get the story right.”

CBS’ ire and the response from the “Truth” filmmakers and distributor Sony Pictures Classics crystallizes the central debate about the incident that has been re-ignited by the film. Was the problem behind the “60 Minutes II” report an issue of corporate interference with the pursuit of a sensitive story? Or was it journalistic mistakes that compromised the reputation of a trusted news outlet and its primary public face, namely Rather?

“Although we understand CBS wants to put this episode behind them, it’s‎ disappointing that they seem to be so concerned about our film,” “Truth” producers Bradley J. Fischer, William Sherak, writer-director James Vanderbilt (“Zodiac”), Brett Ratner, Doug Mankoff and Andrew Spaulding said in a statement.

“The events ‎depicted in ‘Truth’ are still vigorously debated, and that’s a good t‎hing. It’s a fascinating story at the intersection of politics, media ‎and corporate America and features powerhouse performances from Cate Blanchett, Robert Redford and the rest of the cast. We hope people will ‎see the film and judge for themselves.”

At a cast and filmmaker screening in Los Angeles Monday night, Sony Pictures Classics co-president Michael Barker told the industry audience that while the movie would undoubtedly spark heated discussions about journalism, politics and betrayal, “first and foremost this is a movie to be experienced and enjoyed on a big screen.”

“Truth,” which marks Vanderbilt’s directorial debut, depicts the events surrounding the Sept. 8, 2004, “60 Minutes II” broadcast of an investigative report on Bush’s Guard service in the early 1970s. The segment was instantly attacked by critics questioning the authenticity of four vintage memos from Bush’s former commanding officer that were used to bolster the assertion that Bush shirked his duty during the Vietnam era.

The snowballing of specific challenges to the validity of the memos in the “blogosphere” spurred mainstream media outlets — including the New York Times, Washington Post and ABC News — to turn a sharp eye on the internal workings of CBS News. Amid the scrutiny of typefaces, fonts and memo protocols of the era, other figures from the period came forward to question the authenticity of the memos, while the original source who gave them to Mapes admitted he lied about how he had obtained them.

The fallout led to CBS ultimately retracting and apologizing for the report, after staunchly defending it for 10 days. The network’s news division commissioned an independent panel to investigate what went wrong and how such questionable material wound up on the air. In the end, Mapes was fired and Rather announced his decision to step down as anchor of the “CBS Evening News” broadcast prior to the release of the panel’s report in January 2005.

The larger conclusion drawn about CBS’ response to the controversy and decision to appoint an independent panel has stirred the most passionate reaction from the principals.

In Mapes’ book and in the movie, the decision is painted as a politically and financially motivated move to help CBS make nice with the Bush White House and protect the corporate interests of its then-parent company, Viacom, in Washington.

CBS has long asserted that the outside panel was appointed to determine what went wrong and recommend safeguards for the future. It was convened because the credibility of CBS News had been hammered by the memo scandal, which came to be known as “Rathergate.”

Mapes has acknowledged that she made mistakes, but argues that the mainstream media’s focus on picking apart the validity of the memos missed the larger importance of the story about the actions of a future President.

“CBS was concerned about damage to its reputation and wanted to improve it,” Mapes told Variety in a written response. “The film deals with some of that, but it also raises larger issues about the complexities of journalism and the search for ‘truth’ in an increasingly corporate media environment.”

She added, “These topics are much bigger than than the Bush National Guard story and are as relevant today as they have ever been.”

Rather has hailed “Truth” as a spot-on portrayal of how journalists work. He’s prepared for the reaction it will stir. “I hope that its effect is less about questions from the past concerning one particular story, and more about opening up a new and broader debate on the vital role of journalism, particularly investigative journalism, in our democracy,” Rather wrote on Facebook last month after “Truth” screened at the Toronto Film Festival.

Vanderbilt said he, too, is ready to face criticism in taking on the story. He did research in order to capture the “complexity” of the story, he explained, but ultimately the movie reflects Mapes’ point of view. He optioned the book nearly a decade ago after reading an excerpt in Vanity Fair.

“It’s a fascinating, multi-layered story that lives at the intersection of politics, media and corporate America,” Vanderbilt told Variety. “I think the characters are compelling, the story is gripping, and the consequences were enormous. … It’s told from Mary’s perspective, but it raises larger issues about the state of journalism that interested me and enabled us to bring viewers inside the heart of a newsroom. And the reality is that the issues the film raises are just as important today as they were more than 10 years ago.”

The suggestion that the panel’s investigation was a witch hunt to discredit Mapes is the most troubling aspect to those at CBS who have seen the movie. That includes CBS Corp. president-CEO Leslie Moonves, who is said to have screened an early cut about four months ago. (Moonves is not featured or referenced in the film).

Those who were involved in the process say there was never a corporate directive to backpedal on the guard story or fire Mapes prior to the publication of the panel’s 224-page report. And they note that if Viacom had such corporate sway over CBS News, the network likely wouldn’t have allowed the guard story to air two months before the 2004 presidential election.

The questions of Bush’s service record had been chased by many print and broadcast reporters for years. The subject took on heightened importance in 2004 as the Democratic candidate, then-Sen. John Kerry, a decorated Vietnam war veteran, was enduring the “Swift boat” attack from conservative groups on his wartime record.

According to former CBS News president Andrew Heyward, the single-biggest issue in the aftermath of the broadcast was the fact that the authentication process on documents obtained from a source with a history of animosity toward Bush could not be defended by the network. Heyward said he has not seen “Truth.”

“To suggest that what CBS News did was in response to political pressure is completely at odds with how I experienced this very unfortunate series of events,” Heyward said. “It was primarily driven by a media firestorm about our very serious reporting mistakes. That’s how I recall the story.”

The movie makes mention of Viacom’s corporate interests in Washington and the wrangling in Congress and at the FCC in 2003 over a media ownership rule involving the number of TV stations that a company could own. The so-called station cap issue had been a political football — for Republicans and Democrats — but was largely settled by the time the Bush story aired. Those at CBS who were involved in the investigation say the concerns about the station cap issue were simply not a factor in the post-broadcast probe.

“Truth” is even-handed in its portrayal of key CBS News figures who interacted with Mapes during the period. Those getting the most screen time in the movie are Heyward (played by Bruce Greenwood), Josh Howard (played David Lyons), former exec producer of “60 Minutes II”; and Betsy West (played by Rachael Blake), former senior VP of primetime for CBS News. The trio are depicted as news biz pros who were caught up in a fast-moving media storm.

Gil Schwartz (played by Steve Bastoni), CBS’ longtime head of corporate communications, is the only character in the movie who remains at CBS. Schwartz is shown as driving the strategy to defend the report and combat the onslaught of negative media coverage until authentication problems with the memos became insurmountable. The moment marked a turning point for mainstream media reporting being challenged by individuals and entities harnessing the megaphone of online media.

CBS’ investigative panel was co-chaired by Dick Thornburgh, former Republican governor of Pennsylvania and attorney general in the Reagan and first Bush administrations, and Louis Boccardi, former president of the Associated Press.

The presence of Thornburgh was a sign that CBS was looking for a figure who would have credibility with the network’s conservative critics, as Heyward later acknowledged in a deposition tied to Rather’s 2007 lawsuit against the network. Boccardi was tapped to ensure that the panel had the perspective of a veteran journalist. The panel found many mistakes in the reporting process but concluded that there was no political bias driving Mapes or others in pursuit of the story.

As depicted in the movie, CBS News execs were aghast when the document experts that Mapes’ team brought in could not unequivocally vouch for the memos, in part because they were copies. And Mapes is shown dealing with every journalist’s worst nightmare — a source who changes his or her story after the fact.

Externally and internally at CBS, dismay about the problems with the memos was compounded by the fact that Mapes had a distinguished track record at CBS News, where she’d worked since 1989. Just a few months before the Bush report aired, she led the team that broke the shocking story of brutality and human rights violations by U.S. military forces at the Abu Ghraib prison in Iraq — a story that had deep impact and earned many accolades. One former CBS News colleague still calls Mapes the best investigative reporter he’s ever worked with.

The movie is, not surprisingly, sympathetic to Mapes and Rather and their actions after the broadcast. Mapes and Vanderbilt say they sought to be candid about missteps leading up to the broadcast.

“I think the film goes into great detail about some of the mistakes that were made — some of the mistakes that I made — in our reporting, writing and editing. Having said that, hindsight is 20/20 and I did what I thought was right at the time, journalistically and ethically,” Mapes told Variety. “Overall, I believe the heated political controversy smothered some of the truly important elements of our story and what it offered in terms of understanding how class privilege worked during the Vietnam years.”

The events depicted in “Truth” took a toll on all sides. The movie notes that Mapes has not worked in broadcast news since 2004. She has focused on consulting and writing in the years since.

“It has been a difficult transition, but I really value my long career in journalism and I look back very fondly on the bulk of my time at CBS,” she told Variety. “I like to say that I had 15 great years and five bad months there.”

Rather stepped down from the “CBS Evening News” in March 2005 and left CBS entirely after 44 years in 2006. He sued the network, Moonves and Heyward for breach of contract in 2007, saying he was put on ice after the Bush story. The case was thrown out by a New York court. In recent years he has produced long-form reports for Mark Cuban’s AXS.TV (previously HDNet).

Heyward resigned as CBS News president in late 2005, citing the need for a change after 10 years in the post. He now works as a consultant.

Howard and West, who declined to comment for this story, were asked to resign from CBS in early 2005 following the panel’s report, as was Howard’s fellow “60 Minutes II” exec producer Mary Murphy.

Howard, who spent 15 years with “60 Minutes” before his short tenure on “60 Minutes II,” spent several years producing longform programming for CNBC. At present he’s working on a feature documentary “The Lavender Scare,” about the federal government’s purge of gay and lesbian employees in the McCarthy era.

West, who worked for ABC News before joining CBS, is now a professor at Columbia Journalism School and a producer of documentary fare, most recently the 2013 PBS docu “Makers: Women Who Make America.”