United manager Sir Alex Ferguson was so furious at Nani's red card, he took the unprecedented step of not speaking to the media after the 2-1 defeat as he was supposed to under Champions League rules.
Assistant Mike Phelan carried out the duty instead, admitting he was more likely to adopt a diplomatic stance than his boss, who would have risked hefty sanction had he said in public what he thought in private.
The gagging order was extended to United's playing squad, who were similarly simmering, so at least UEFA can have no axe to grind on that score.
However, Rio Ferdinand sarcastically applauded Turkish referee Cuneyt Cakir after the final whistle and United will need to wait to see if any reference is made to it when the assessor's report lands at UEFA on Thursday.
If the incident is flagged up, Ferdinand can expect to face some kind of sanction, given UEFA were happy with Cakir's performance.
"There are no issues for us regarding the sending off," said a UEFA spokesman.
"We will wait for the official reports of the match delegate and the referee's observer. If they raise concerns we will act."
Ferguson is due to speak to the media on Friday ahead of Manchester United's FA Cup quarter-final with Chelsea.
There has been an element of circling the wagons at Old Trafford, with Roy Keane's observation that Nani deserved his punishment for a high tackle on Alvaro Arbeloa coming in for stinging criticism.
Former United European Cup winner Paddy Crerand was particularly venomous, although others were equally incredulous.
"That decision was an absolute joke," former United defender Viv Anderson said.
"The players will feel as though they have been cheated by the referee."
Another ex-player, Lou Macari, said: "He was the same referee who sent John Terry off in the semi-final last season.
"When I read that I thought surely he is not going to be one of those who brings out yellow cards for fun.
"He brought a red out for fun instead."
Once his anger has subsided, Ferguson will be able to reflect on an outstanding first hour in which Danny Welbeck and Ryan Giggs were superb.
However, should the United boss watch the match again, he may concede Rafael could easily have been sent off for a handball on the line.
He may also wonder at the speed with which Real adjusted to their numerical advantage, turning the entire tie on its head before United sorted themselves out.
As Phelan pointed out, United are used to recovering from such shattering reversals of fortune and Sunday's FA Cup quarter-final with Chelsea is almost perfect, given the Red Devils have home advantage against a side mired in their own problems and tired by a midweek trip to Romania.
And although Europe remains the pinnacle, a fourth domestic league and cup double would be welcomed with open arms at Old Trafford.
However, if it all goes wrong for Ferguson's team, a season that promised so much will suddenly not appear quite so positive, given the general acceptance that a 20th championship is already secure.
"If you are in the next round of the Champions League, all the pressure for Sunday is off," said Macari.
"You get knocked out of the Champions League and suddenly you have a big game on Sunday. It adds a little bit of pressure.
"The players have to go out and deliver.
"It is not a foregone conclusion, though, and all of a sudden, from us talking about the treble, this defeat is an example of why it was silly.
"So many things can go wrong.
"I just hope they can rise to the occasion on Sunday."