Yeah, as far as I can tell the rules were properly followed so I don't have any complaints on that front.
What I'm talking about is whether those should be the rules. It's foul play, obviously, and a yellow doesn't feel unmerited. But it didn't seem to me to be the kind of totally egregious action that should have resulted in such an extreme penalty. Players will inevitably make mistakes on the pitch, and I think the margin between legal and red card should be larger than it seems to me to be.
I dunno, I haven't played Rugby beyond high school PE class, and I only really watch Six Nations and World Cup so I'm no expert on the sport, but it currently feels excessively punitive over small differences.