After the match SAF seemed resigned that the card could not be rescinded, and that was the rules.
However, it does seem a grave injustice that Fletcher will miss the biggest match of his life because an official got it disastrously wrong. It is also unfair that whoever United play should be handed an advantage, when the tackle was very good and fair.
It has been pointed out that if a player had thrown a punch last night, and the referee had missed it, then retrospective action against that player, including a ban on that player could be taken.
I cannot see anyone thinking this mistake should be allowed to stand "for the good of the game" when everyone, including the referee by now, knows that an honest man has been condemned.
As every Champions League match is televised, surely an amendent to the rules of the competition to allow video evidence to overrule the referee in incidence such as this, on appeal.
If United do contest the decision, they will probably fail because they knew the rules of the competition before they entered it.
Not a good day for football though.