I can at least wrap my head (no pun intended) around the notion that some people would want Thomas Elliot to be the guy under the bandages (though it didn’t really bother me because I don’t have a particularly high opinion of that character). What I don’t really understand is the desire to include the fake Jason Todd sequence. Jason hasn’t even been mentioned in this film series yet, and viewers are not likely to know him and his backstory unless they’ve watched Under the Red Hood–a story that occurred after Hush and which now sits in the pre-Flashpoint Paradox animated film universe.
There’s only one way I can imagine including Jason Todd in this film. First, Jason would actually have to be Hush. Otherwise, it’s not worth the amount of screen time required to set up the character. Thomas Elliot can still be his accomplice. In fact, the most logical development would be that he saved Jason’s life on the surgical table but then faked his death so that he could brainwash Jason into becoming Batman’s enemy. Why do it that way? Simple. We need to satisfy our second point: most of the side characters and side plots would have to go. We need space to establish both Elliot and Todd, so we can’t be tracking Poison Ivy to Metropolis and meeting up with Superman. We can’t have the Riddler or the League of Assassins and their Lazarus pits at all. It really just has to boil down to this premise: someone is trying to kill Batman, and the clues point to Jason Todd. No abducted child or ransom money. No Scarecrow or Clayface. Really, no one but Nightwing and Catwoman. In other words, we lose most of the book in order to preserve the last three issues of the book, and even then, the ending still has to change.