defensive holding

[Biscuit]

I had this happen in a game last fall and after doing a little research, I have decided that I didn't call it right. I am on a wing. I have a defensive end on most plays simply grabbing the offensive tackle and wrestling him to the ground. No effort to make a play on the ball carrier. He was basically giving himself up in order to take the tackle out of the play. I brought it up to my WH during a timeout and he said there was nothing wrong with that. In looking at rule 9-2-3c, it says a defensive player shall not use his hands or arms to hook, lock, clamp,etc in an effort to restrain an opponent other than the runner. Am I interpreting this correctly? During the game was no time to argue with my WH about it and I wasn't sure of the rule. It just didn't seem right for the DE to do that. What's your position/expirience with this?