Tottenham Hotspur eventually booked their place in the quarter-finals with a 6-1 win over third-tier strugglers Rochdale.
But, not for the first time this season, the action on the field threatened to be overtaken by debate over the VAR, which is being trialled in English cup competitions this season.
Mark Halsey, a former Premier League referee, said Spurs’ Erik Lamela had had a “perfectly good goal” disallowed for a minor infringement by Fernando Llorente when Wednesday’s game was still goalless.
There were several other flashpoints at a snowy Wembley, with referee Paul Tierney ruling out Son Heung-Min’s penalty for Spurs after the South Korean star paused in his run-up — another decision which involved a VAR check.
When asked about Lamela’s ‘goal’, Halsey told BBC Radio Five Live: “For me it wasn’t a clear and obvious error. I thought it was a perfectly good goal. I don’t know why it was referred (to the VAR) in the first place.”
Halsey added he did not understand why the referee did not look at the touchline monitor himself, as allowed under the protocol.
He also criticised Tierney for ruling out the Tottenham penalty, saying he should have had the spot-kick retaken for encroachment.
“He could have handled it better,” Halsey added.
Tottenham manager Mauricio Pochettino, speaking after the match, said: “The first half was a little bit embarrassing for everyone. I’m not sure that system is going to help.
“We love the game we know, football is about emotion but if we are going to kill emotion then people who love football will not be happy,” he added.
Meanwhile Spurs full-back Danny Rose said the VAR was “shambolic” and an “absolute disgrace”.
“We got the job done under shambolic circumstances through the game,” Rose told talkSPORT radio.
“An absolute disgrace, waiting around for I don’t know how many minutes to get a decision.
“It’s just laughable,” he added of a system where players and fans alike are kept in the dark over a referee’s reasoning, unlike similar set-ups in cricket and rugby.
“It just ruined it a little bit.”
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