Bothroyd appeared to be brought down in the penalty area by the outstretched leg of Matt Connolly when bearing down on goal, only for official Kevin Friend to wave play on.
"I've gone through in the penalty area and the guy has left his leg out," Bothroyd told the South Wales Echo. "He didn't get the ball and took me down, yet the referee didn't give a penalty.
"Then Craig Bellamy ran through. He was in the box and their guy pulled him by his shirt - everyone can see the big V from the back of his shirt. Once again he didn't give it and it's inconsistent. He (Friend) is a Premier League referee as well.
"I don't understand why referees are untouchable. For me if you make a mistake you hold your hands up and say I made a mistake. I don't understand why referees can't do that.
"He waved me away saying it was never a penalty. I'm going through to score a goal, he's brought me down. I don't understand. Why would I go down if it's not a penalty?"
The TV replays of the incident reveal just how blatant a foul it was.