Corrected entry: Towards the end of the movie, Danny Roman piles up a huge amount of office furniture as a barricade and ignites it with a grenade of some kind. Flames appear almost immediately. When he counter-attacked the corrupt SWAT team some scenes before, he threw quite a lot of the same type of grenades without creating one single flame.
Corrected entry: After the marksman has a clear shot of Danny but refuses to shoot him he is asked to stand down and is presumably replaced. There is then a scene with Danny in the, now broken, window where we see 4 or 5 laser sights on his chest and one on his forehead. One of those is coming from the helicopter and one may come from the replacement shooter but where do all the others comes from and what were those marksmen doing when there was a clear shot earlier? It's stretching credibility to imagine that one marksman was replaced by four new ones in the few seconds that have passed.
Corrected entry: In the scene where the hostage taker is negotiating with Farley and says he can't use the word "no", it is exactly what happened in the Richard Bachman/Stephen King book "Rage." Even some of the dialogue is taken from the book.
Corrected entry: While interrogating Niebaum soon after taking the hostages, Danny talks about Neurolinguistics. Danny says that if someone's eyes move in a certain way it means they are lying, in another way means they are remembering, etc. He is close, but not exactly right about how Neurolinguistics works. Each person does have a set of eye movements that allow a trained interrogator to tell if they are making up statements, but those movements are not the same for everyone. It takes even a highly skilled interrogator several minutes (at least) of questioning on known topics to be able to determine an individual's signs. Danny would not have been able to just begin asking questions like he did and use Neurolingustics to determine if Niebaum was telling the truth, and if the department trains its negotiators in this skill it certainly would train its Internal Affairs agents, the men who have to interview dirty cops, on the same skills.
Corrected entry: Throughout the negotiations, Danny Roman uses his radio to communicate with (and in some cases, manipulate) the police force. So when Roman finally "convinces" Inspector Niebaum to confess to his part in the set-up and to name some of the other people involved, why wouldn't he use his radio so the entire police force could hear the conversation?