You have to feel for them. It's not studs up... but there is still a lot of force on that standing leg. They'll call it endangering an opponent, but I think nine times out of ten you don't get sent off for that.
That's a harsh red. Such an important game, at this even stage, I wouldn't give that. Given that it's not one of those challenges that's a clear red, you have to be cognizant of context.
Nah, between yellow and red was the one in Italy vs Wales. This is very much on yellow territory. Very low, not studs up, just a mistimed late tackle but normal in games.