Manchester City boss Roberto Mancini and his players were furious with ref Chris Foy during their FA Cup defeat to Manchester United.
The flashpoint came early in the first-half with skipper Vincent Kompany's dismissal.
The Daily Mail says footage on their website shows just how angry Mancini and his players were at Foy's performance.
Kompany is seen describing the decision as "******* unbelievable" as he heads down the tunnel while, at half-time, Mancini tells Foy to "look and look well" at TV footage of the tackle.