Mark Hughes was angry at referee Graham Poll after Blackburn lost to Manchester United in the Carling Cup semi-final.
The semi-final was taking place at Old Trafford
Poll awarded a penalty to United after Zurab Khizanishvili handballed but waved away appeals when Rio Ferdinand appeared to do the same.
Hughes said: "Mr Poll thought 61,000 people had come to see him. Referees have to remember fans come to watch two teams play, not the referee.
"I am particularly disappointed with the penalty decisions."
He added: "How the first one was given I've no idea - and our one was more blatant but was not given.
"We had a very similar, if not stronger claim early in the second half which wasn't given.
"Okay, it was a great save by Brad Friedel and that didn't cost us, but there were a number of other decisions right through the game that led to frustration on our part.
"I feel there needed to be a balance in the amount of decisions we had and that Manchester United had."
United boss Sir Alex Ferguson praised Blackburn keeper Brad Friedel for his performance but believes his side's second half performance was key to their victory.
"The players realised that if they didn't match them for effort then we were going to suffer and they raised the tempo of the game," he said.
"I thought we were a bit casual in the first half and maybe getting a goal a bit early can do that here.
"We tried to play relaxed but in cup ties it is sometimes difficult."