Toure - who won three Premier League titles during his time with the Citizens - believes the referee's decisions influenced the result and questioned why the officials didn't use the pitchside monitor to review the key decisions.
"I have this sense of injustice for City," he told Premier League Productions. "The penalty was a big call. Why do they have the screens if they don't use it?
"Of course it's difficult as it's sensitive - Liverpool are a big team in a big stadium.
"It was a great game but I'm disappointed as a City fan."
Toure added: "This is the first year I've seen City with a lot of players injured.
"Leroy Sane, Ederson - they are great players and so important in this line up.
"I think it's quite hard to say the title is over - but I hope City will recover."