The Laws say it's a red card if he deliberately hits a player in the face with his hand or arm. It wasn't really deliberate though as his arm deflected off Emerson's shoulder. I also don't think it was two yellows as Havertz fouled Richarlison before Ziyech did. But the elbow on Romero was a clear red card.
There's no reason that he couldn't book both, but it looked like Ziyech was getting it, to me. I didn't think he'd do either, given the standard he'd set, until he stood over Richarlison.
I said it at the time but I thought the ref had a great game. I rarely comment on refs too but I’ll give credit where it’s due, especially at a time where refs are constantly being scrutinised both on here and in general. He let most 50-50s go unpunished which for a derby (and just in general) was nice to see, sick of games constantly being stop started over petty barges or taps. The game flowed quite nicely on Sunday and that’s how matches should be. He blew for proper fouls and booked those who went over the line. If anything, one of his only mistakes actually went in our favour and that was not booking Richarlison for deliberately preventing a counter attack but he blew for the foul so hardly a huge issue.
Weird behind the scenes video with odd angles and a strange colour filter: Chelsea's kit and some random gingers look quite... off.