The 34-year-old defender had guided a header beyond Gianluigi Donnarumma, 26, following Erling Haaland’s, 25, opening goal, but an assistant referee soon raised his flag for offside, arguing Andy Robertson, 31, had been impeding the goalkeeper’s vision.
Now, Slot has insisted that it was “obvious and clear” the goal should have been allowed.
Speaking with Sky Sports after the match, the Liverpool head coach said: “It is difficult to give my view. It is obvious and clear that the wrong decision has been made, at least in my opinion.
“[Robertson] didn't interfere at all with what the goalkeeper could do. Immediately after the game, someone showed me the goal that the same referee allowed - City against Wolves last season.
“So it took the linesman 13 seconds to raise his flag to say it was offside. So there was clearly communication, but as I said, that could have influenced the game in a positive way for us.”
Even if the goal was allowed, Liverpool would have still suffered a defeat to The Citizens, with their Premier League game on Sunday (09.11.25) ending 3-0 to Manchester City.
Liverpool’s loss is the Reds’ fifth of the season, of all which have has come from their last six games.
As a result of their defeats, Liverpool have fallen down the table to eighth place with 18 points after 11 games - eight behind the current leaders Arsenal.
Slot reflected: “I don't know if that is the situation. It has been a very good start to the week, with a very bad end to the week.
“Today, I don't think, apart from that decision, that it was ever going to be our game. In general, they were the better team - we need to improve - but I didn't need this game to know this.
“I saw a team trying to come back into the game, but it wasn't enough today and that is clear.”
The manager then played down Liverpool’s defence of the title, and insisted the Reds instead needed to “focus on our performance”.
He said: “Last season, when we were eight points clear, it didn't feel like it was done already," he said.
“We shouldn't talk about the No. 1 position [in the Premier League], we should focus on our performance that needs to be better.”