We have no idea what his coach was saying. He may have been telling him what a great kick he just made and what to do on the kickoff. He may have been chastising him, we have no idea. As a coach, I will occasionally grab a player by the face mask when he is overly excited to make sure he is facing and looking at me and listening to what I am telling him, which is often positive, sometimes negative.
But even as a coach, I will often let a player know he did something wrong whether it deserved a flag or not. In the first example, where the player dropped (not slammed) his helmet in disgust, I would certainly have a discussion with him letting him know that is not acceptable behavior. But "not acceptable to me" and "deserves a 15 yard penalty" are not necessarily the same thing. In the second case, I may need to settle him down because there is still a kickoff to be made.
