CRAIG LEVEIN reckons Lee Wilkie was sent off because ref Kenny Clark FORGOT he had already booked the United stopper.
Wilkie was given a second yellow for persistent fouling just three minutes from time.
But the whistler's delay in raising the red suggested he didn't at first realise he had booked Wilkie already, for a 77th minute flare-up with Barry Nicholson.
And Levein believes Clark would have thought twice about dishing out a soft second yellow if he'd realised its consequences.
He said: "Lee thought Kenny didn't know he had booked him already and it looked that way because there was a delay between the yellow card and the red.
"Only Kenny can tell us but I felt Lee was unfortunate. It seemed so innocuous for a second yellow card.
"It's frustrating because there's a knock-on effect for our next game with two players now suspended."
While Levein (below) had sympathy for Wilkie he refused to defend skipper Barry Robson who saw red for a two-footed lunge on Chris Maguire that sparked a mass brawl between the players.
He added: "In the modern game you cannot tackle in an overly aggressive manner - and that's what Barry did so I've no complaints.
"The young boy didn't get hurt but Barry went in such a manner then with the melee that followed there's only one decision. I can't blame the ref.
"It's a bad day at the office. We just had too many players performing below the level we have been recently.
"If it had been one area of the team then a substitution or two might have helped - but we can't make the seven substitutions we needed."
Meanwhile Dons goal hero Sone Aluko wants to extend his loan from Birmingham City. Initially signed to January, Aluko said: "There are so many big games to look forward to and I'd like to extend my loan for the season."
