Play was waved on after his second half challenge on Ruud van Nistelrooy amid howls of protest but minutes later and before the derision had died down, referee Rob Styles pointed to the spot following Gary's challenge on Ole Solskjaer.
"I think the first one, I haven't seen it but everyone has told me, looked a blatant penalty so I was lucky there," reflected Gary.
"The second was very clumsy of me. I'm really disappointed with it."
Gary insists, however, that it was not a case of trying to ride his luck.
"That's what it might have looked like! It was stupid really, especially after the first incident, to go for the ball in the box.
"Like I say, I'm really disappointed. You get these things in football, so I am going to have to try and put it behind me and learn from it."
Penalty incidents aside, it was a big performance from Gary alongside Dean Richards in the heart of defence and they coped admirably with United's varied threats.
"I suppose I've got to take the positives. It's all very well saying I had a good game, but I cost us the game. I'm still young and I'll learn from it, take it on to the next game and hopefully perform better."
Gary Doherty admits that he stretched his penalty luck a little bit too far on Saturday against Manchester United.