The game at Old Trafford ended in a 1-1 draw after Javier Hernandez had given United an early lead in the second half while Newcastle striker Demba scored with a penalty.
Referee Mike Jones appeared to give a corner to Newcastle following a fair tackle by Rio Ferdinand on Hatem Ben Arfa, but he was persueded to award a spot-kick after talks with his assistant John Flynn.
“In real time I thought it was a penalty, and you could tell from the players’ reaction it was tight,” he told Sky Sports.
“Looking at it again, the ball has changed direction, but whether he took a little bit of Hatem before he took the ball is debatable.
“It is one of those that I’m sure Man United and Sir Alex will be really disappointed about, and for us it was a break.
“But I thought we played well enough to deserve a break.”
“Forget about the result, the performance was outstanding and I think in the first half we were the better side,” he added.
“We were heroes at the end because when you get a guy sent off you all have to pitch in, but we have been doing that all year and that is why we have had the results we have.
“It was an outstanding display from the goalie and the back four, but it is not unusual.”
