The wall calendar inside Lt. Roberts' office is for January 1959 while the wall calendar just outside his door is for September 1963.
The large circular card file on top of a file cabinet in Lt. Roberts' office changes position as he dismisses everyone to speak with Rojack alone. It continues to change positions in many other shots of the office as well.
From inside Cherry's room, the red "Hotel" sign is flashing. From outside the sign is on steadily.
As Cherry is driving Rojack from the nightclub, the same white car can be seen in the rear-projection background twice, as Cherry turns and it keeps going straight.
The rear-view mirror in Cherry's blue car appears and disappears. It is missing in the close-up shots through the windshield, but is present in location shots of the car from a longer distance.
As Rojack is sitting on the ledge of the penthouse, Kelly continually blocks and unblocks a studio light which is reflected in the sliding glass door behind them.