Revealing mistake: After Sam nearly falls down the elevator shaft, the scene fades and comes back in with Sam speaking to the landlord about the incident. The landlord brushes off Sam's hat with his hand and hands it to him. The brushing motion was played in reverse first to extend the length of the action.
Revealing mistake: Sam is getting shot at in the aircraft hanger. He hides behind a yellow machine and a bullet hits it. The bullet produces a flash but leaves no mark where it hits. A real bullet would have left a gash at the least.