Let's just hold up for a sec, this is rugby, the goal is to dominate and hurt the other player, correct? This is a contact sport, correct?
He obviously didn't mean to knock him out, but an attempted big hit gone wrong when the ball-runner slips at the last second, causing the chest high tackle to turn into a head high tackle. He also passes as Heinz goes in for his tackle, and this happens, it's rugby.
Unfortunate, obviously, but if he didn't get knocked out it wouldn't even be looked at.
So let's just relax for a sec,
Can he even get suspended if he did not receive a red card?