Sean Dyche admitted VAR was beginning to "test his patience" after Everton had to settle for a goalless draw in their FA Cup third-round tie at Crystal Palace following Dominic Calvert-Lewin's harsh red card.
With Everton pushing to break the deadlock in the second half of a tight game at Selhurst Park, Calvert-Lewin slid in to win the ball from Nathaniel Clyne, with Chris Kavanagh, the referee, allowing play to go on.
But with Clyne staying down after the challenge, Craig Pawson, the VAR, recommended Kavanagh conduct an on-field review, with the referee then handing Calvert-Lewin a straight red card despite the striker making minimal contact with the Palace defender's shin.
Everton suffered a further blow when Dwight McNeil was stretched off - although Sean Dyche said the midfielder was "OK" - but they held on for a deserved draw, with Palace now set to visit Goodison Park for the replay.
How Calvert-Lewin decision halted Everton's hunt for cup win
Having been knocked out in the third round in three of their last four FA Cup campaigns, Palace kept changes to a minimum after beating Brentford last time out - although Roy Hodgson did finally hand a first start to £26m summer signing Matheus Franca.
However, it was Everton - who made just three changes themselves - who started the game on top, with Arnaut Danjuma forcing Dean Henderson into a smart save.
The Palace goalkeeper then had to be sharp to kick James Garner’s low corner off his line, before Jefferson Lerma fired the hosts' only chance of the first half over the bar.
Eberechi Eze finally forced a save from Joao Virginia - starting in place of the rested Jordan Pickford - early in the second half, but Everton continued to look the more likely to open the scoring.
Calvert-Lewin should have done more than provide Henderson with a simple save after finding space in the area, before his evening went from bad to worse thanks to his controversial dismissal.
The officials somehow deemed the 26-year-old to have committed serious foul play, meaning he will now miss Everton’s next three matches.
But Everton were not deterred and continued to push for the winner, with James Garner and Jack Harrison both lashing wild finishes over the bar.
McNeil then exited the game after falling awkwardly, which prompted Palace to belatedly hunt a winner, going closest when Virginia tipped Eze’s long-range shot wide.
There was still time for a half-hearted Everton penalty shout when Beto threw himself to the floor under pressure from Joachim Andersen, but Kavanagh appeared to make the right call in turning down the appeals - despite Dyche's protestations.
But the hosts were unable to truly test Everton’s No 2 and will now have to win at Goodison if they want to progress to the fourth round, while the Toffees will be grateful to have ended a four-game losing run.
Dyche: Why bother going to the monitor?
Dyche questioned the purpose of referees being called to the monitor, saying: "Every fan must think, ‘what is the point?’
"We all know the outcome - they’re going to agree with everything they’ve been told. I don’t know what the stats are but the chances of something getting turned down are miniscule. Why even bother?
"I’m a fan of VAR but I just don’t get looking at the screen."
Asked for his thoughts on the much-maligned system, Dyche said: "It seems a bit confused at the moment. It needs tidying up. I thought it was getting tidied up but it seems to have taken a step back. It’s beginning to test my patience."
Dyche also thought his side should have had a late penalty, telling ITV: "If you’re going to slow-mo things, you’ve got to slow-mo what could have been a penalty on Beto.
"He’s got his arms clearly round him, cupping his body."
Hodgson: It was a 'modern-day' red card
Hodgson admitted he was slightly confused by the decision to send off Calvert-Lewin, telling ITV: "I don't know if I can understand those things these days. I don't know what to make of it.
"The fact depends how far you want to go back in the past because I'm certain there’ll be lots of people who played in the past watching, saying, 'No, that's not a red card'.
"But then people playing recently will possibly say it's a red card because of the way the studs were up, and he was leading with a straight leg.
"I think it's unfortunate for Calvert-Lewin and it certainly wasn't a vicious foul by any stretch of the imagination.
"I thought the referee actually refereed the game quite well. There was a lot of decisions to make, a lot of challenges because both teams were relatively physical, so I thought he handled that fairly well.
"If the decision is a red card, so be it, I suppose. But I'm not prepared really to come out and say definitely it was, or definitely it wasn’t. I think it's a modern-day situation."
What's next?
Crystal Palace's next game is on Saturday January 20 when they travel to Arsenal in the Premier League; kick-off 12.30pm. The Eagles then host Sheffield United on Tuesday January 30; kick-off 8pm.
Everton's next outing is at home to Aston Villa in the Premier League on Sunday January 14, live on Sky Sports; kick-off 2pm. The Toffees then go to Fulham on Tuesday January 30; kick-off 7.45pm.