Andoni Iraola lashed out at the officials following Bournemouth's 1-1 draw with West Ham, accusing them of going back on a pledge to stop penalising unintentional handballs.
Enes Unal scored a stunning 90th-minute free-kick to cancel out Lucas Paqueta's penalty, as Bournemouth extended their unbeaten run to four Premier League matches.
The Cherries have scored more goals in the 90th minute than any other side in the Premier League this season (six), while their eight goals via substitutes are also a league-high figure.
Despite the result keeping Bournemouth sixth in the Premier League, three points adrift of the top four, Iraola was left fuming at the award of West Ham's 87th-minute spot-kick.
Tyler Adams' arm was behind his back when it was struck by Aaron Wan-Bissaka's cross, but following an on-field review, Chris Kavanagh awarded the penalty.
Speaking to Sky Sports after the game, Iraola claimed he had been told by referees in pre-season that such offences would no longer be penalised, saying: "I am very disappointed.
"We have had this meeting before the season and I argued personally because they don't want defenders to defend with their hands behind their back.
"I told them, 'we are going to continue this because you are calling penalties'. They said 'don't worry, it's a natural position, we are not going to call it'. Then the first one, bam.
"I am very disappointed. I complained about this rule. They didn't want defenders to defend unnaturally."
Asked if he would seek an explanation from the officials, Iraola added: "I don't care about the explanation now. I want them to take the decision they say they are going to take. Today it didn't happen."
Bournemouth's 29 shots in the game was their second-most in any Premier League match, only recording more when they fired off 32 against Sheffield United in March.
However, Julen Lopetegui was impressed with many aspects of West Ham's performance, as they moved seven points clear of the relegation zone.
"We were very close to winning against a very good team. When you are very close there is frustration to lose these two points," Lopetegui told BBC Sport.
"But there are positives against a very demanding team in Bournemouth. We deserved to win at Leicester. Today we did well too.
"Above all, I want to highlight the behaviour of the group. All the players want to work very hard to do their best for the team.
"This is the first step to be strong, to be a better team. We are going to keep this positive mentality."