"It's a bit frustrating to say the least," said Ut boss Kevin Blackwell.
"Where he's got the time from I don't know but you can't complain about referees, can you?
"We knew it was going to be tough and there was all the stuff about Neil Warnock coming back but we dealt with that and looked as though we were going to win.
"We should have been smart and kept the ball in the corner at the end. It's a cruel game and I'm sick, to be honest."
Palace boss Neil Warnock hailed team's battling qualities.
He said: "It was a great fightback and I'm proud of them. We never give in."
Warnock singled out Patrick McCarthy for special praise after the defender turned in a good performance a week after suffering a dislocated shoulder.
"I thought he was magnificent," said Warnock.
"He was still a bit sort yesterday, which was understandable. A consultant told him that if he could stand the pain, he wouldn't cause any more damage.
"It was one of those games where you had to be tough. It would have been cruel on him if his alleged push on Beattie for the penalty had cost us the game. I don't think the game deserved to be decided by that."