The Lincoln (car) that McMillan and Enright are driving shortly before midnight changes models from a 70s model to a 60s model.
When McMillan is entering the elevator at gunpoint, the interior of the elevator is wood panels, the next shot of him in the elevator has metal panels and then there are wood panels again.
It is daylight as the detectives are waiting for McMillan to enter the elevator, when he exits and goes onto the roof, it is night.
When Mac shows Feliciano how the alarm is set off, he has to radio to have the alarm reset and it takes a while after that for it to stop ringing. Later on, when Mac takes custody of the painting, however, the alarm stops on its own when he returns the frame to the easel.