Sir Alex Ferguson admitted Gary Neville should have been sent off during the first half of Manchester United's 2-1 win at West Brom.
Javier Hernandez's 75th-minute header proved enough to give United a narrow victory at The Hawthorns and keep them top of the Premier League.
But the Baggies were seething at referee Chris Foy's failure to punish Neville's first-half lunge on Graham Dorrans with a penalty and a red card.
Neville certainly did not touch the ball as Dorrans, with only Tomasz Kuszczak left to beat, tumbled to the ground. And even Ferguson accepted Foy got it wrong.
"Gary was lucky to stay on," said the Scot. "It was a penalty. At first I thought he had got a touch but when I saw it again, he was lucky."
As it turned out, Peter Odemwingie missed a later spot-kick for the hosts. And Ferguson added: "If you miss a penalty playing at home, midway through the second-half, it is a bad blow. If they had scored, they would probably have won the game because they had the momentum."