When the three men are looking for the red van after the wedding, they keep in contact with each other using hand-held radios. But in one scene during their conversation, the man on the motorcycle is talking to the others with both hands on the handlebars.
In many shots of the exterior of the army tank, the head of the actual tank driver can be seen in addition to the character who is supposed to be driving it.
When Bear is aiming the bazooka at the truck for the first time, it is obviously empty.