Sean Dyche believes Burnley should have taken all three points at Watford after Chris Wood's injury-time strike was controversially chalked off for offside.
Wood latched on to Dwight McNeil's shot, which had been parried by Ben Foster, to put the ball in the net, but Burnley's celebrations at Vicarage Road were cut short.
TV replays suggested Wood was played on by defender Jose Holebas, but Watford, off colour for much of the afternoon at Vicarage Road, survived.
"I thought it was onside and I am surprised the goal wasn't given," said Dyche.
"I don't know how it works anymore because I thought if the decision is tight, it goes in favour of the forward.
"I am not jumping up and down about it because it is tight, and the officials were good today, but in my opinion, they got that wrong."
VAR will be introduced to the Premier League next season, and Dyche added: "It is a must, it's a given. "Obviously there will be teething problems, but we all questioned goal-line technology, and whether it would slow the game down, but it hasn't."
Burnley, who headed into the fixture bidding for a fourth straight win, were the better of the two sides.
Ashley Barnes had the chance to hand the visitors the lead on the half-hour mark, but his header lacked power, and Foster averted the danger.
Barnes was involved moments later, but shanked his effort wide when the ball fell kindly to him following Christian Kabasele's mistimed clearance. After the interval, McNeil then smashed his volley over the bar from six yards out.
"I felt like it was a winning performance," added Dyche. "We had golden chances and we didn't take them."
Watford remain seventh in the table, but their performance here was a frustrating one, greeted with jeers at the interval and full-time, too.
Abdoulaye Doucoure, who is keen to leave Watford amid reported interest from French giants Paris St Germain, was a notable absentee from their starting line-up.
Javi Gracia said his omission was owing to a minor knee injury sustained in last weekend's victory at Crystal Palace, but that he will be available for their next game against Newcastle.
Gerard Deulofeu should have put Watford ahead inside two minutes but failed to find a way past Tom Heaton.
The Burnley goalkeeper then denied Troy Deeney on the stroke of half-time, but Doucoure's presence was sorely missed.
"I don't like to speak about the players that I don't have available," said Gracia.
"There are others like Tom Cleverley, like Etienne Capoue, who both have played very well."
Quizzed over Doucoure's future, the Spaniard replied: "I answer that question every day. I don't have any news about that. I think he will be my player until the end of the season."
The Watford fans stood to applause Graham Taylor in the 72nd minute after holding their scarfs aloft before kick-off, two years on from his death.
Gracia added: "We wanted to get a victory on a special day for the club, but if you don't play at your best, then that doesn't happen."
