After the match, Liverpool legend Jamie Carragher cut a bemused figure, not quite sure how his old team had gotten away with Wirtz's goal.
He said, "I know sometimes the angles can fool you, but the fact that we've got the penalty spot to look at, I just can't believe that's been given."
However, there is still a margin for error with the Premier League's semi-automated offside system. While offside is given to the millimetre in the Champions League, for instance, the Premier League's VAR setup operates with a tolerance of up to five centimetres - effectively, the width of the green line. Wirtz was, therefore, awarded the goal because his foot was inside the green line, falling into the VAR's margin for error.
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