Arsenal were denied victory over Brentford on Saturday due to 'human error' by the official in charge of VAR, it has emerged.
Ivan Toney's controversial equaliser at the Emirates Stadium cost the Gunners three points, opening the door for Manchester City to potentially cut their lead at the Premier League summit to three points when they host Aston Villa on Sunday.
According to the Telegraph, VAR operator Lee Mason failed to check whether Christian Norgaard was in an offside position when he crossed for Toney to score.
Arsenal boss Mikel Arteta was fuming that the goal had been allowed to stand – although not for the same reason.
After the game, Arteta complained that Brentford defender Ethan Pinnock prevented Gabriel from challenging for the ball while in an offside position – which was checked, but no offence was deemed to have been committed.
Pinnock headed down for Norgaard to set up Toney's 74th-minute leveller – and while no Gunners players appealed at the time, it has since been shown that Norgaard was standing just offside.
The result means Arsenal have now dropped points in successive matches for the first time all season, following last weekend's shock 1-0 defeat at Everton.
And next up for Arteta and co. is a decidedly enormous clash: they host Man City on Wednesday night.
