I thought a yellow was ok. It was petulant and worrying from our perspective but was, in terms of contact, nothing much. We got the benefit of the doubt (unlike with Fellaini who is not allowed to breathe) - I don't see it as more than that.
ye I don't see the big deal either, even my mate who's an Arsenal fan hasn't said anything about it. clear yellow, arguably a red but I think the ref made the right call...and it's not because I'm a United fan