What I take from this is that if you want to cheat and hold on to players you should do it, because if the other player doesn't react you won't get caught, and if he does react he'll get worse punishment than you. »
Ridiculous that that can be a red card. If you lift a person by both legs and drop him, then ok, but if you lift one leg and drive him back so he falls over, then i don't see what the problem is. He didn't lift the player off the ground.
I think the excuse of 'he just has a poor tackling technique' goes out the window in professional sport. His job that he's paid for is to have good technique, so if he's so incapable of doing that then he shouldn't be allowed to play, because he's a danger for other players. Hernandez didn't drop or change direction at the last second so there's really no mitigating factor here.
If World Rugby wasn't such a joke they'd ban Ngwenye for dangerous play. This isn't just an unfortunate, unavoidable accident - it's him being completely incapable of doing the basics. And if that means he's a danger for others, he shouldn't be allowed play until he learns not to be a danger.