Waratahs coach Michael Cheika has ripped into Argentine referee Francisco Pastrana's officiating in their 30-19 Super Rugby loss to the Bulls.
The irate Aussie said while Pastrana's performance with the whistle did not cost them the game it robbed them of valuable momentum.
"I am very disappointed with the officiating, the communication, the language, the ability to decipher and the correct decisions," Cheika said.
"We made plenty of mistakes as well mind you, but even with all those mistakes we were still dominating the attack side of the game."
Bulls captain Pierre Spies said that he could find no fault with Pastrana's performance on the night but admitted that the sides coming up on top generally had little to complain about.
"I think the officiating was good tonight both ways some calls might have been questioned but it was consistent," Spies said.
"I felt the referee was easy to speak to and easy to listen to and he was clear in his descriptions but when the result goes your way you are always happy."