Sheffield United's penalty was the correct call from the ref. To be honest, I thought Michael Oliver had a pretty flawless game yesterday. Didn't have a lot to do but got pretty much every decision spot on.
Side note that's more about the commentary than the refs: I was unreasonably pissed off at the fact that they were trying so hard to make that Maguire incident a thing. That sort of challenge happens week-in-week-out and nobody bats an eyelid, but as soon as it's us suddenly the commentators are saying it should've been given.
This was doubly frustrating because, a few minutes later when Brewster checked Amrabat from behind whilst Amrabat actually had control of the ball, the commentators made some snide comment about it being "a shoulder charge back in the day" and implying that it shouldn't have been a foul.
I don't at all believe in any refereeing conspiracy nonsense, but I do think the media treat any incidents that happen in our games very differently to any other side.