To be fair I was ready to say "no" because a flat out punch would have been too much from a grown man but actually, just grabbing him and shoving him off when he's following and repeatedly hitting him doesn't seem that excessive. Obviously there are much bigger issues going on with this kid though... he's not ended up like that for no reason, and it looks like he's on a very bad and very angry path that will most likely lead to him getting properly hurt when he's a bit older.
His exaggerated "hurt" reaction, too!

... transitioning into a demonic "**** YOU *****!!" as soon as he realises they saw the whole thing.
Also how short is that guy they're actually pretty much the same size