Revealing mistake: After Jonny Lee Miller gets shot in the head, he slowly falls into the water, facing Sara and Gabe. In the next shot, he has turned towards the water. If you watch closely, you can also see him turn his head so he doesn't hit the face on the water surface. (01:34:15)
Revealing mistake: When Gabe fights with Lucas, if you look closely the entire time "Lucas" is actually a stunt double.