I don't think any of these things are the key point. You can call it a bump, protecting himself, a collision or anything else. It's just semantics really.
This is the key point and the thing he can't do is go high and make contact.
He can bump/protect himself/collide as much as he likes and all is well but he can't do that and go high and concuss someone. That is the only reason he is in trouble.
If he had gotten low and made hip/hip contact then we wouldn't be talking about this now.
(And before someone says that's contrasting with the Dangerfield one, they are completely different incidents).