Revealing mistake: At the start, Doc shoots one of the watch towers that explodes. However, it explodes in a way that shows it to be made of something other than concrete. Something like card. (00:05:30)
Revealing mistake: When the tanks are firing on the building near the end, some of the shots of shells hitting the building are reused. (01:35:00)
Revealing mistake: When Barney shouts at Christmas in the pickup to go right, there are already skid marks on the floor from a previous take. (00:20:05)
