Other mistake: Powell says he has a desk job, but he is driving a cruiser. Cruisers are for cops on patrol. A cruiser would not be issued for a cop at a desk, especially not one who's on his way home, as Al says he is.
Other mistake: When Frank and the Ghost of Christmas Past are at the office Party where the younger Frank is still working, as they stand by the entrance door two women leaving move in closer to try and avoid bumping them - despite the fact that the Ghost said earlier they couldn't be seen or affect what's going on.