Brunei DPMM head coach Steve Kean suggested that the S.League follow the example of the Premier League by allowing club officials to speak to referees after games.
The ex-Blackburn Rovers boss was furious that his side were denied an added-time penalty by referee Ahmad A'Qashah as they fell to a 1-0 defeat at Choa Chu Kang Stadium on Sunday night.
DPMM seemed certain to win a late spot kick after an apparent handball by Warriors centre-back Kento Fukuda, but Ahmad waved play on. After the final whistle, Kean and his players surrounded the official before DPMM's Najib Tarif was shown a red card for dissent.
"I asked the FAS spokeswoman and she said that it was not advisable to speak to the referee," Kean said. "When I was in the EPL, I spoke to officials like Mark Clattenburg after matches, who was more than happy to speak and answer any questions as long as he was given a 15-minute leeway after the match.
"You would [ideally] like to put your point of view across and get the views of the officials, but sadly that does not happen in the S.League."
Earlier, DPMM had a penalty awarded against them when stand-in goalkeeper Awangku Mu'izzuddin felled Shaiful Esah in the box. However, Warriors' new striker Andrei Ciolacu sent the resulting penalty against the left-hand post.
"When you see the first penalty, it was soft and tough on us," Kean said. Obviously [Mui'zzuddin] is going towards the ball and one of the Warriors' players blocks him and wins a penalty.
"I felt it was justice that they did not score the penalty. When you compare that to the incident at the end, the referee simply has to give it.
"The Warriors staff and the Warriors played both apologised to me for it, and everybody in the stadium knew it. It has to be a penalty and it cost us a point."
The defeat was DPMM's ninth in 11 games this season to leave them second last on the table, above only developmental side Garena Young Lions.
For fourth-placed Warriors, it was a much-needed boost after a two-match winless streak.
"I'm very much relieved and it was a great win today, especially after coming into this on the back of a defeat to Tampines Rovers and a draw against Garena Young Lions," Warriors coach Razif Onn said.
"I was happy with Andrei's [Ciolacu] performance, but I thought he could have done more individually. It's, however, good to see that he is getting the shots, and had a couple of good chances. He needs to settle down before I can have higher expectations of him."
Warriors FC will play Home United in the Singapore League Cup on Friday while Brunei DPMM face Tampines Rovers a day later in the same competition.