Thought Probert had a decent game, got the key decisions correct and seemed in control of most of the minor stuff and, apart from one flashpoint, players seemed happy and respected decisions.
With regards to Smith's red card, my initial thoughts were that Walcott still had a lot to do for it to be a DOGSO, but, when you think about it, he had scored running in from that kind of area only 5 or 10 minutes earlier so I think it's probably fair to describe that as an obvious opportunity to score a goal. Not an obvious goal but certainly an obvious opportunity, which is all it needs to be.
Could've avoided the Smith-Richarlison confrontation if he'd given the clear free-kick for Richarlison clattering into the back of Smith, which is what had clearly incensed Smith, but a ref can't be blamed for their minor error leading to player stupidity.