Revealing mistake: During the (second) bank robbery, the ceiling was frequently unusually close to the top of the robbers' heads (inadequate clearance), indicative of a poorly positioned green screen (or CGI). (00:16:35 - 00:17:00)
Continuity mistake: When Detective Knight and Casey are playing cards, the positions of the cards, cigarette box, and loose cigarettes change several times. Near the end of the scene, Casey's view of the cards does not show a "bet" cigarette below the cards, but there's one there when he gathers the cards. (00:11:54 - 00:12:47)
Continuity mistake: The "Santa" carrying the Molotov Cocktail walked up the steps and past the decorated handrail, but he was standing within the length of the handrail (about mid-way) when the camera shifted from the right-rear to left-rear side. (00:02:40)