The Scot had previously declared that he "does not want his players diving" after Young was booked for an attempt to win a penalty against Crystal Palace back in September.
But Moyes defended the 28-year-old over claims that the winger was guilty of simulation in winning a penalty in a midweek Champions League draw with Sociedad, saying that he had not seen fit to speak with the player about the incident.
"I didn't see an issue at all," the former Everton manager told reporters. "The referee was 2 yards away from it and gave a penalty. If you need to talk to anybody, you should ask the referee. The question is loaded towards the player. That is wrong. The question should be, 'Did the referee get the decision right or not?'
"He was 2 yards away from it. For me, where I was, I definitely thought it was a penalty. Everybody can now stand back and watch it from TV. I was one of many who said I would definitely have retrospective action for diving because it would make the referee's job much better. But on the night, if you had said, 'Could you get the referee any closer?' I don't think he could."