Objectively I think that when the keeper comes out and makes an honest attempt but misses the ball and punch the player in the face with the force of a thousand fists, it should be a automatic red card and penalty. I also think the keeper should be allowed to challenge for the ball with the same force as defenders do, and despite the awkwardness of his arms being that high up, it really wasn't that bad. He is allowed to touch the ball with his hands, yet if his hands were down you wouldn't consider the force to be reckless in it self like in a shoulder to shoulder situation. So the question should not be if it looks weird, but if the keeper is using his hands in a dangerous manner that could hurt the player. That should be the rule for these types of situations. Gives you some protection for the keepers but even if you indeed get unlucky, just punching a player in the face or in the head should lead to a red card every time.