Yes, it was a penalty and that's exactly what VAR is supposed to be for. Apparently, they didn't review because his arm was by his side, except that it wasn't, of course. If they had looked properly they would have seen his arm well away from his body and a penalty all day long.
He was ok by Prem standards. Way better than Salisbury, Atwell and Bankes, better than Taylor, on a par with Mariner, Atkinson and a few others. We could have had a pen and they could have had a couple more yellows.