Dundee United boss Craig Levein has accused referee Stuart Dougal of arrogance following his side's 2-1 defeat by Celtic.
Levein had a pitchside confrontation with the official after he refused to allow Terrors defender Lee Wilkie to receive treatment for a knee injury.
"He (Dougal) lost his composure, stuck his finger in my face and told me to shut up," fumed Levein.
"It wasn't acceptable. In all my time in football, no other referee has ever done that.
"I have lost all respect for him after the way he spoke to me.
"If it happened in the pub on a Saturday night to any of you guys, the guy would have got a punch in the face.
"I asked him why he didn't stop the play for Lee Wilkie to get treatment and I don't think that is unreasonable.
"If you were Lee Wilkie and you had been out of the game for three years, you would be upset.
"It is compounded by the fact that he wouldn't let anyone come on, he didn't believe him.
"If he wants to look at the stud mark above Lee's shin he can do that."