A clearly riled up Guardiola remonstrated on the pitch at half-time and was duly sent to the stands by referee Antonio Miguel Mateu Lahoz and the Spaniard explained what decisions he clearly felt were mistakes from officials.
City went on to lose the overall tie 5-1 on aggregate, but the former FC Barcelona coach feels it could have been a totally different outcome if the officiating were at a higher standard.
"I said he was wrong," he said after the game, as quoted by Sky Sports. "I didn't insult him. I just said it was a penalty and it was a goal. "The ball [for Sane] came from (James) Milner. He said, 'From Milner it came?'. 'Yes, from Milner'.
"When it comes from Milner it is not offside, and we go to half-time 2-0. Two-nil against that team is a little bit different.
"In these kind of games, in these competitions, the impact is so big. At Anfield the first goal from (Mohamed) Salah is offside. The goal from Gabriel Jesus in Anfield was a goal, not offside."
Citizens playmaker Bernardo Silva also had his say on the matter via his official Instagram account after the game.
"Thank you all for the support and amazing atmosphere tonight! We gave everything we could so no regrets," Silva wrote. "Next year we'll be back to try again! Congratulations to Liverpool and good luck on the semi-finals.
"Ps: Champions League could you guys start using the VAR next season? It might be useful."