The door behind Don is open when seen at 1:19:55 or earlier and closed whenever seen following 1:20:07. At 1:20:42, the door opens when Mrs. Baker rushes past Don, and, in the next second, it is obvious that Don was nowhere near the door.
At 1:42:19, the position of Don's hand on the ladder changes.
At 1:00:38, the way Jill holds things changes and then reverts.
Jill and Don leave their apartment so he can show her where the laundry is - 44 steps to the right of the apartment entrance, which is at 1355 Grant Avenue. However, they arrive at the Toy Sun laundry, which is at 1521 Grand Avenue - two blocks and more than 44 steps away. Also note that they walk past Mooney's Irish Pub at 1525 Grant Avenue next door to the laundry.