Visible crew/equipment: When Jack is in the library towards the end of the movie, he looks in a room and then the shot goes back to facing him. If you look very carefully, in the back of the hall you can see a person walk by. He is very hard to see. (01:49:05)
Suggested correction: You never see anyone walk by. It's only him and his friend Jason. It's also very dark in the hallways so may have been a shadow.
Visible crew/equipment: When the janitor is approaching the door you can see a shadow of a man, which isn't the janitor's, in the background holding something that appears to be a microphone. (00:30:05)