I was watching the game live and believe this was an incident where the VAR system could and should have worked perfectly. When it happened I immediately thought it was a penalty and I could fully understand why the ref gave it. However, the replay quickly showed that it should have been a free kick to Villa. Therefore, the VAR should have overturned the original decision. It was relatively straightforward as far as I was concerned.
Villa boss Dean Smith said: "I can understand Jon [Moss, referee] getting it wrong, but I don't know what VAR are looking at."
That's the way I saw it. In real time, it looked a penalty. The replay showed it wasn't. I think the ref's mistake was an honest one. The VAR's failure to overturn the incorrect decision was the problem.