Revealing mistake: When Ryback jury-rigs a timed explosive to destroy the helicopter, he uses a tin of paint thinner which is expected to fall off a hand grenade, thus releasing the spring on the grenade. However, when the explosion occurs you can see over Ryback's shoulder that the paint thinner tin hasn't moved at all, and that the explosion occurs inside the helicopter, not where the grenade was placed.
Revealing mistake: When Seagal kills Tommy Lee Jones, he either sticks the knife into his head or smacks him on the top of his head with his fist (it's not that clear). But what appears to be clear is that this is in fact a dummy head or a stunt double - it looks very unlike Lee Jones.David Mercier
Revealing mistake: When Ryback busts out his fellow mates and hands out weapons to them, the Uzi given to one of his mates does not have a magazine in it. (01:02:20)