Like anyone who wasn’t on the Justice League set, i don’t know the full story, so i can’t know for sure what kind of people all who were involved are, but based on this article, it sounds like Joss Weedon became the scapegoat so that Hamada, Jhons and Berg could get away with shitty behavior involving all 4 of them
I seriously doubt that Ray Fisher’s only complaint was that he didn’t get enough screen time, ’cause if that was the case, he would’ve been fired and recast instantly, probably without any media coverage of it, trust me, no buisness would go thru such a hassle if the complaint was so petty, especially not for someone who’s just up-and-coming