The problem with the replay booth guys is that if they start second-guessing the field call, then the thinking is, the guys on the field will be less likely to call it. I think the booth guys were given the same "all things being equal, throw the flag" speech as the field guys. I have yet to see one get overturned, and a lot of ones where the contact is, at best, incidental because the offensive player is lowering their head to deliver a shot. The defensive player at full speed, if he's trying to adhere to the rule, is already going low to avoid the head/neck area, and the helmets end up colliding. Those are the worst calls because there is literally nothing a defensive player can do in that situation.Can't help you in regards to the review booth, just passing what an on-field official told me they were instructed to do. Once it goes to the booth it's out of their hands.