Hearts head coach Robbie Neilson blamed referee Willie Collum after a 3-2 defeat by Hamilton at New Douglas Park ended their 100% league record.
Collum sent off Hearts' Callum Paterson for a challenge on Darian MacKinnon with the visitors leading 2-1.
Neilson disputed the red card and even claimed he was expecting one of his players to be sent off when he found out who the officials were.
"The game has been ruined by a decision that is not a sending-off," he said.
"We are sitting 2-1 up and we get a red card against us that I don't think is a red card and it totally changed the flow of the game.
"We actually practised during the week going down to 10 men because of the environment we're coming to and the officials who are taking the game and we have to do that.
"In the recent past, the statistics involving the officials have shown a lot of red cards against us, so we have to prepare for it.
"The next time we get these officials, we will again train with 10 men."
Neilson is adamant the result will not have a negative psychological effect on his players.
He said: "Believe me, they are highly motivated - highly motivated to get back to training and work hard because they know what we have to deal with."
The result leaves Hamilton just four points behind Hearts and unbeaten at home since February.
Their player-manager, Martin Canning, believes the sending-off was the turning point but was understandably delighted with the outcome.
"It had everything," he said. "It was a great advert for Scottish football.
"The referee decided to flash the red card, but I didn't really see what happened.
"I still believed we could get back in the game, but when they are down to 10 men, it gives us that little bit of momentum again."