It's not often you hear a director talk about how good a movie might have been, but wasn't, as Josh Trank did on the eve of this weekend's box-office belly flop of his "Fantastic Four."

Indeed, the "Chronicle" director's tweet, quickly deleted, may have helped sink the box office for Fox's $120 million Marvel superhero reboot. The film, which had been tracking for a $40 million opening weekend, pulled in a feeble $26.2 million, finishing behind the second weekend of Tom Cruise's "Mission: Impossible – Rogue Nation."

The savage reviews of the film, which was at an abysmal 9 percent positive rating on Rotten Tomatoes, were the primary culprit.

Also Read: 'Fantastic Four' Fails, Tom Cruise's 'Mission Impossible' Sails at Box Office

But it couldn't have helped when Trank responded to the critical pans Thursday night with a since-deleted tweet: "A year ago, I had a fantastic version of this. And it would have received great reviews. You'll probably never see. That's reality though."

On Sunday, one box office analyst told TheWrap that Trank's online outburst might have cost the film $5 million to $10 million — especially since fans of comic-book movies tend to be less swayed by official critics than by auteurs like Trank who are seen as more authentic defenders of comics culture.

Despite the fallout, it's unlikely that Trank could be in any legal jeopardy for seeming to undercut the commercial prospects of the film.

"We stood behind Josh's vision for the film as we stand behind all of our filmmakers at Fox," Chris Aronson, the studio's veteran distribution chief, told TheWrap.

Representatives for Trank have not yet responded to TheWrap's requests for comment.

Also Read: 'Fantastic Four' Review: 10 Minutes of Michael B. Jordan-Kate Mara-Miles Teller Chemistry, 1 1/2 Hours of Bad Story

The weak opening for "Fantastic Four" is a big blow for Fox, which was hoping to capitalize on the enduring popularity of comic-book movies with a younger cast led by Miles Teller, Michael B. Jordan, Kate Mara and Jamie Bell.

Instead, the film's opening was less than half the $56 million that the first "Fantastic Four" managed in 2005 and the $58 million debut of its 2007 sequel, "Rise of the Silver Surfer." It also broke a 12-film run of No. 1 openings for Marvel movies that dated back to 2012.

There were also signs of trouble with Trank well before his social-media outburst. During last year's filming in Louisiana, the filmmaker clashed with the studio and producers Hutch Parker and Simon Kinberg, who rewrote the script. The completed "Fantastic Four" had a different ending and many critics cited its lack of continuity in their criticisms.

Also Read: 'Fantastic Four' or Fantastic Flop? 9 Critics' Most Scathing Reviews

While rare, examples of directors slamming their own movies are not unprecedented. Tony Kaye, another first-time feature director, objected to the cuts and changes made by New Line Cinema prior to the release of the Neo-Nazi drama "American History X" in 1998. He fought unsuccessfully to have his name removed from the credits and replaced by Alan Smithee, a pseudonym used by directors looking to disassociate themselves from a project.

Edward Norton went on to receive an Oscar nomination for best actor for the film, and the high-profile dispute may have helped at the box office. The stakes were far lower than on "Fantastic Four," a big-budget film for which Fox had franchise aspirations. "American History X" cost $20 million to make and brought in $23.8 million globally.