I can't help but feel that a thick padded glove hitting a helmet, both of which are designed to protect against 120mph pucks, won't do any long term damage, if indeed it's even felt.
I can't help but feel you're watching a different video?
Both gloves and helmets appear to be off in most cases on here. It seems normal practice for hockey players to shed these prior to fighting.
I don't think I would want to be on the end of too many of these...