He didn't see the 'stamp' incident as he was looking the other way. So I am not minded to criticise him for that because he would have gone on what the fourth official saw or didn't see.
Having said that, I think he should have clamped down on Shrewsbury's niggling fouls earlier - and I am surprised they didn't get more cards. I think the commentary said he was fairly inexperienced (?) - he looked it at times anyway.
OK, but not brilliant.