Kavanagh did not originally blow for a foul but the incident was brought to his attention by VAR and he opted to give the centre back a straight red after reviewing footage on the pitch-side monitor.
Karren BRady has slammed refereeing in the Premier League as the worst she has ever seen
The West Ham chief was reacting to the club having Fabian Balbuena’s red card rescinded
But Balbuena had his ban overturned after a successful appeal by the club and will now be available for Monday’s game with Burnley.
A similar incident occured earlier in the season when Tomas Soucek’s red card at Fulham was also rescinded.
Hammers’ chief Brady used her column in The Sun to take aim at the level of officiating in the top flight and insisted that VAR has not helped those in charge of the game.
Balbuena was sent off for catching Chelsea’s Ben Chilwell after clearing the ball up the pitch
She wrote: ‘The Stockley Park mob, blinking in front of an array of screens, may get more offsides right although, goodness knows, they often do so to the fury of people who don’t see any sense in arms or shirt sleeves being involved.
‘The refereeing itself has been poor this season, possibly the worst I have seen in the Premier League.
‘No doubt there will be statistics that prove me wrong but, subjectively, I can remember no time when the whistle was so out of tune with the game.
‘VAR was sold to us as a way of perfecting decisions. These two red cards alone proved the opposite: not until the refs were requested to look at the screen did sendings off seem even a possibility.’
Tomas Soucek also had a red card overturned for a similar incident earlier in the campaign
West Ham boss David Moyes also criticised the decision to send off Balbuena after the game.
He told Sky Sports: ‘I think it’s a decision made by someone who’s never played the game before.
‘Where is Balbuena meant to plant his foot? If they do think that’s a red card, the same one a few minutes later between Coufal and Rudiger is a very similar challenge. They didn’t do anything about it.
‘You have somebody who doesn’t know the game. He kicks through the ball, and not for one minutes is there a bit of malice in that. It’s a rubbish decision.’