Revealing mistake: In one of the war flashbacks Stephen carries the wounded Dodge through a trench. They pass by a screaming pig, but in slow motion you can see that it's just a motionless carcass. (01:01:05)
Revealing mistake: When Tristan kill the guy in the liquor storage and the hay fork goes through his chest, you can see that parts of the hay fork's tines closest to his body are not covered with blood. (01:51:05)