Liverpool avoided a first Premier League defeat of the season on Saturday as they came from behind to beat newly promoted Aston Villa 2-1 at Villa Park.
While the visitors dominated possession in the first half, it was Villa who took the lead, with Trezeguet meeting a John McGinn cross at the back post on 21 minutes.
A VAR check for offside saw the goal stand and there was more VAR misery for Klopp and his players minutes later.
Roberto Firmino found the net for Liverpool, but was denied the equaliser as VAR reinforced the linesman's decision to raise his flag.