Wenger moaning about it:

‘Mertesacker made the challenge but I said he got Mertesacker sent off. You cannot say it’s not true.
‘In the first game he got Gabriel sent off and today he got Mertesacker sent off. It was quick and harsh. I didn’t know if Costa was offside or not or if Mertesacker touched him or not. I would have to watch it again. But a fact is the fact. I do not accuse him of anything. It’s just what happened.
‘Costa has got two players sent off in two games on our side. So he’s clever.’



So what about the 2 points from 9 Arsene? What's the excuse for that? The ref? The pitch? Costa?