In the scene where Indy is pushed off the side of the tank, the strap of his cute little leather purse gets tangled up on the barrel of the gun. Great tension here as the tank heads toward a big rock. However, the gun from which he hangs is the same one which was blown up by the rock he had shoved into it earlier and it is all flared out on the end like a giant metal flower. This means the strap would have had to go all the way around the end of the gun. And to make matters worse, when he hoists himself back up, the strap is instantly free from the gun. There just wasn't enough time for all this to happen.