One of the biggest reasons why Avengers: Age of Ultron remains one of the most expensive films ever made is that it was the first time the cast demanded paychecks that they felt they deserved. But the behind-the-scenes drama wasn’t pretty, according to a 2013 Deadline article, that quoted numerous industry insiders as saying that when many cast members threatened to walk out, Robert Downey Jr was forced to stand up for them against Marvel.

According to the report, which was published shortly after the release of Iron Man 3 and the announcement of Avengers 2, several actors tried renegotiating their contracts with Marvel, after being paid a ‘pittance’ for their first appearances. Even Robert Downey Jr, who reportedly earned around $70 million for the first Avengers movie and even more for Iron Man 3, publicly attempted to get a salary hike by hinting that he may be done with the character. In an appearance on Jon Stewart’s show, he said, “I don’t know. I had a long contract with them and now we’re gonna renegotiate.”

The report quoted an insider as saying, “Some received only $200,000 for Avengers and Downey got paid $50M. On what planet is that OK?” This caused some bad blood behind-the-scenes. “Marvel has created so much animosity by strong-arming and bullying on sequels already. It’s counterproductive,” another insider said.

Reporter Nikke Finke wrote that she’d heard “Marvel already has threatened to sue or recast when contracts and/or options are challenged. That prompted a few cast members to respond, ‘Go ahead.’” She wrote that Chris Hemsworth in particular wasn’t too keen on returning for more Thor films, especially after a less-than-pleasant experience working on Thor 2. “I also understand that Scarlett Johansson told castmates she’s ‘not going to cut her quote’ for the film,” Finke wrote.

“To counter,” Finke continued, “I’ve learned the Avengers cast are becoming united behind Robert Downey Jr who is seen as the ‘leader’ – like ‘a big brother’ in the words of one rep – for all the younger actors in the ensemble.” One insider noted, “He’s the only guy with real power in this situation. and b*lls of steel, too. He’s already sent a message that he’s not going to work for a place where they treat his colleagues like sh*t.”

Deadline asked director Joss Whedon about the drama, and while he defended Marvel, he said, “I’m not going to comment specifically because I’m not privy to that sort of stuff and I don’t think it’s my place to talk about. In general terms, yes – Marvel can be very cheap, God knows. They can also be sensible and frugal. They have a very small infrastructure and they’re not heaping this money on themselves.”