Don't expect Hollywood. 'Denial' is British in spirit.
It is a puzzle to me that all the promotions I have seen for Denial insist that Rachel Weisz has to prove that the Holocaust really happened. There are hundreds of hours of newsreels to prove that, and hundreds of survivors of the death camps, not to mention liberators and railroad records and documents including confessions to prove that. And anyway, that's not what she's asked to prove.
Weisz plays the real-life woman who was sued by a real-life historian because she said he knew he was lying when he said Hitler knew nothing about the Holocaust and had nothing to do with it. This is a British libel case, and the burden of the evidence is on her, so she has to prove that Timothy Spall knew he was lying in his defense of Hitler; and considering the capacity for self-delusion in the human mind, I'm not sure she was ever able to prove that.
Weisz had promised the survivors of the death camps a voice in the trial, and she wants to confront the vile Spall herself. The movie audience will probably share her wants, despite the horrors that will involve.
But Denial is British in spirit as it is in historical subject, so don't count on Hollywood stereotypes. You can count on sophisticated writing and acting, and startling Timothy Spall, and new and convincing concept of court action, and a generally grown-up movie.