Slaven Bilic said the introduction of the video assistant referee (VAR) in the Championship would prevent penalty decisions from having a damaging impact, citing how such judgments can dictate managers getting “new contracts, praise or the sack”, after West Brom and Derby both suffered from questionable officiating in an entertaining draw.

Kenneth Zohore scored a spot-kick for the second time in four days to preserve Albion’s unbeaten start in the league but their equaliser six minutes from time came courtesy of a dubious penalty awarded against Derby’s Max Lowe, who went to ground to halt Matheus Pereira.

In the first half the goalkeeper Sam Johnstone denied Martyn Waghorn, who gave Derby the lead from the penalty spot, from 12 yards after Filip Krovinovic was penalised by the referee Gavin Ward after his assistant, Mark Pottage, flagged for handball despite Lee Buchanan’s seemingly harmless cross appearing to strike the midfielder’s right shoulder.

By the end Bilic was close to combustion, with the exasperated manager sent off late on after the referee awarded Derby a goal-kick when Jason Knight superbly blocked Jake Livermore’s close-range effort to prevent Albion from snatching victory.

“I don’t like double celebrations, I don’t like disappointment in the crowd and of the players when a goal is disallowed, that you have to wait one minute or two minutes but that will be cut down – it needs practice,” Bilic said.

“But at the end of the day what VAR brings is justice and it’s truth and it’s fair and in the business of that scale or stage, when it is so important when people are getting new contracts or praise, the sack or getting made redundant [as a result of such decisions], it is very important. We need justice and fair decisions. I was always the first one to say that for the referees, it is not difficult; it is impossible to see everything.”

Jake Livermore rises above Derby’s Kieran Dowell. Photograph: James Williamson - AMA/WBA FC via Getty Images

It was a case of deja vu for West Brom in more ways than one, with Zohore striking a late leveller from the spot as he did on Wednesday after another sluggish start. West Brom teased only glimpses of the style and swagger synonymous with Bilic’s arrival and it was not until the Croat introduced the West Ham loanee Grady Diangana and Pereira that Albion truly came alive.

Bilic had spent much of the first half slapping his thighs in anger and Derby, who travel to Nottingham Forest on Tuesday, did not do a lot wrong but squandered several chances to put the game to bed before Albion denied Phillip Cocu a maiden home win.

Jack Marriott and Jason Knight, the teenager who shone on his full league debut, missed chances to move out of sight, with the former skewing wide in the second half, while Johnstone dived to his left to keep out Waghorn’s second spot-kick of the afternoon.

“If he scores the second penalty I think victory is ours,” Cocu said, before praising Knight, one of three Derby academy graduates to impress. “What’s not to like about him?” the Dutchman said. “His presence in the game, just a 18-year-old boy – he’s breathing football.”

The reality is that justice was served – but failure to take advantage of a gift from the officials came back to haunt them when Pereira went down under pressure from Lowe. “I warned the lads at half-time, because we got two penalties, ‘anything happening in our 18-yard box can be dangerous,’” Cocu said. “We made a mistake and they took advantage of it. We gave a solution to the referee. If he [Lowe] stays on his feet, what can he [Pereira] do? Nothing. It’s hard, it’s tough on us but that’s why we don’t have the three points.”