Dolan was in charge of Reading on a temporary basis for Saturday's 1-0 defeat at Old Trafford after Brian McDermott was controversially sacked earlier in the week.
Wayne Rooney's deflected, first-half goal condemned the visitors to defeat and left them seven points from safety in the relegation zone.
But it could have been a different story had referee Mason awarded Reading a penalty in the second half for a blatant push on Adrian Mariappa by United's Nemanja Vidic.
And an annoyed Dolan said: "It was a clear penalty but I think the referee thought I was on work experience and, 'perfect a little 1-0 loss for Reading' and would be fine.
"I wouldn't have expected that from the referee but what can you do?"
Meanwhile, Dolan has expressed his shock at Reading's decision to axe McDermott on Monday.
"No-one was more surprised than me," said Dolan. "It is well documented that Brian is a good friend of mine but the decision was made and we move forward."