The main talking point from United's relatively routine 2-0 win over Sunderland on Saturday was the apparent mistaken identity that saw Wes Brown sent off instead of John O'Shea.
Referee Roger East appeared to send off former United stalwart Brown in error, after TV pictures showed that it was another ex-Red John O'Shea who committed the offence.
The fact that the incident involved two former United players only added a touch of irony to the confusion.
Referees body Professional Game Match Officials Limited (PGMOL) said East thought Brown, 35, had fouled Radamel Falcao in the incident that led to Wayne Rooney scoring from the penalty spot.
O'Shea appeared to pull the Colombian back but Brown was dismissed.
While there may be controversy over the sending off, there could be little argument over its impact or the result that leaves Sunderland deep in the relegation mire.
The two Black Cats centre backs spoke to East following the red card, but, despite the official also consulting his assistants, he stuck to his decision.
A PGMOL statement after the match, said:
"From his position, Roger East, the match referee, believed he saw contact from John O'Shea and Wes Brown.
"As he thought Brown had fouled Falcao as he was in the act of shooting, he dismissed Brown for denying a clear goalscoring opportunity in the second phase of the play.
"After the incident, the match referee consulted with his team of officials, but none were better placed to offer guidance."
United manager Louis van Gaal said on the incident:
"The players protested because they felt the wrong player was sent off, not because they felt the penalty was wrong.
"That's a mistake, you make mistakes as well and so do I, it can happen.
"It is unlucky but we deserved to win."
Sunderland intend to appeal the decision- which they would not be able to do for two bookable offences.
If the appeal is successful, O'Shea would serve the one match ban instead.