Jurgen Klopp believes Chris Kavanagh's decision to award Everton a second-half penalty at Anfield was the wrong one.
And the Liverpool boss said he was denied the opportunity to question the official after the game in the wake of a fourth successive home loss in the Premier League.
The champions were beaten 2-0 as the Toffees secured their first win across Stanley Park since September 1999 on Saturday night.
Gylfi Sigurdsson doubled the lead for Carlo Ancelotti's side after Dominic Calvert-Lewin went down from a challenge by Trent Alexander-Arnold.
After being asked to consult the pitch-side monitor, referee Kavangh upheld the decision from which Sigurdsson sealed a famous win for Everton.
Klopp said questions over whether he thought it was a penalty were "unfair" as he disagreed with the call to hand Everton the spot-kick.
The Liverpool boss said: "I really think it is unfair to ask me because everybody asks me that question, so it means everybody thinks it was not a penalty.
"But that is not really important because the referee thought it was a penalty.
"So I wanted to talk to him after the first few interviews I had but he left already.
"I just wanted to ask what did he see because when the VAR calls you over to the sideline then I think he is in doubt about the decision.
"But he needed only a second [to decide]. So he went there, had a look and give a penalty, so he obviously saw something other people didn't see.
"I haven't seen it back yet but everyone who speaks to me tells me the same. How can it be a penalty? So..."
