Plot hole: In the lobby of police headquarters, Danny Roman's lawyer tells him to make a deal with the prosecution. Danny turns to his wife Karen and tells her to wait in the car and he will be right back. Then he proceeds to go upstairs and overtake Niebaum's office. Much later when Chris Sabian is negotiating, Karen arrives on the scene wondering what's going on. How long was she waiting in the car? (00:28:35)
Suggested correction: This isn't a mistake. Karen (and anyone else still on the property) would have been sent away by the police once they became aware of the hostage incident. She went home to wait for Danny because she doesn't know he is the perpetrator. When she is called back to the scene by Sabian she wonders what is going on because she doesn't know that Danny has taken hostages in the building.
So she drove there with him and then just leaves him there? Lol. Can't see her just leaving without him since they drove there together. Even if people went around telling everyone to leave the area, I just can't see her not hanging around and waiting for him.
Plot hole: In the final scene Sabian gives the bogus discs to Frost who crumbles them up. After Frost is shot outside, Sabian is helping Danny Roman out of the house, he is holding the discs in his hand. Since they couldn't find the real discs and the computer was destroyed what were these discs he was now holding?
Suggested correction: This isn't a plot hole. Danny is just holding presumably blank discs. They couldn't find the wiretaps so Sabian tricked Frost by pretending the discs he were holding were genuine. Since Frost admitted on the radio to everything and there are literally dozens of witnesses, they don't need the wiretaps anymore. Danny is just showing Frost exactly how Sabian tricked him: he's still alive and he was fooled by false evidence.