Balbuena was shown a late red card by Chris Kavanagh following a lengthy VAR review, with the Paraguayan dismissed for serious foul play having caught Ben Chilwell with his studs after clearing the ball.
Kavanagh had not even given a free-kick before being told to review the incident by VAR Peter Bankes.
There was no sign of intent or malice from Balbuena, while team-mate Vladimir Coufal found himself in a similar position minutes later with a challenge on Antonio Rudiger - but no card was shown.
“For me the big thing is it’s a really rank, rotten decision and it shouldn’t be given,” Moyes told reporters.
Earlier, Moyes had told Sky Sports “I think it’s a decision made by somebody who has never played the game.
“I don’t know where Fabian Balbuena is supposed to plant his foot.
"If they do think that, then you’ll look at the one a few minutes later which was the same with Vladimir Coufal and Rudiger – it was a very similar challenge but they never did anything about it, so is there a consistent message to both of them?
"I don’t see how it’s a red card. He’s kicked through the ball, I don’t think for one minute there’s a bit of malice in that trying to catch him. I thought it was a rubbish decision.
“But we’ll go again, we’re in a decent position, there’s games to play and hopefully we are right in the mix for some form of European football right to the end and I’ll keep trying to push to make that the Champions League if we can."