Revealing mistake: When Angela knocks the nurse's computer monitor down, there is only a power lead seen, no data lead to connect to the tower.
Revealing mistake: In the scene where Angela is in jail, she goes to make her one phone call. When she is talking on the phone you can see that the receiver is already in the down position, meaning that the call is already disconnected.
Revealing mistake: On the beach, after Jack kills the mugger, he "cuts" himself with a knife to appear heroically injured. As the moon glints over the blade, it is obvious that he is pressing the back of the blade into his palm. (00:26:05)