@Larksea I think that that's exactly where a lot of people disagree with you.
That was a shoulder charge pure and simple, any mild involvement of the left arm was there for the red to find an out, not to be part of a legitimate tackle.
He was never going to dislodge the ball with that, Watson would need to have been a good foot taller and been completely upright to have had a hope in hell.
SBW was going for a shoulder charge with the intent to hurt his opponent, and I don't think his brain was engaged in the act beyond the most minimal of ways. Whether he was aiming for the head or not only he can know, but the thought is far from lunacy.
SOB was an attempt to help in a tackle, and the very act of wrapping his arm is what caused the head contact, and absolutely no intent to hurt anyone was ever part of it.
So one is an illegal act designed to hurt, and one is a legal act designed to not to hurt. Both ended up hurting.