SANZAR officials have all but accepted responsibility for a farcical refereeing blunder that cost the Brumbies victory in Sunday's 36-34 Super Rugby defeat to the Bulls, labelling CJ Stander's try a "stone-cold mistake".

But they've chosen to back South African referee Marius Jonker for his overall performance despite Brumbies coach Jake White openly questioning what ended up being a heavily lopsided penalty count of 14 to six.

The Brumbies came achingly close to the upset of the season on Sunday after outscoring the Bulls five tries to two at their lauded fortress of Loftus Versfeld Stadium to finish up just two points adrift at the final siren.

But SANZAR game manager Lyndon Bray admitted on Thursday the Bulls' second try was awarded in error - with both Jonker and assistant referees Lourens van der Merwe and Stefan Breytenbach missing a clear knock-on from Morne Steyn.

Stander ran on to score from the midfield after everyone else - including his Bulls teammates - stopped and waited for a whistle.

"That particular error is just a stone-cold mistake," Bray said.

"He's just got to put his hand up and say `we got it completely wrong'.

"That was between the assistant referee and the referee and that cost seven points.

"And that probably colours the overall view of the performance because of that mistake."

White has otherwise demanded a please-explain from SANZAR, disputing the number of penalties that were awarded against his squad.

In the end, they proved the difference, with Steyn notching a game-saving 26 points off his own boot.

"I need to know what we have done wrong or what we need to change," White said.

"It's like any feedback - it's very hard to start changing things if everything I see is OK."

Bray defended Jonker for his decisions, saying that while some were "quite harsh", the Brumbies were clearly under increased pressure while in defence.

"I'm backing him on the big picture of it because the Bulls were able to get in behind the Brumbies' defence on a few occasions which put them under pressure. In that scenario you are more prone to sinning.

"(But) was it the best performance of the weekend? No.

"It was reasonably solid and you'd probably say it was acceptable, but you'd want it to be better."

White also questioned how the Bulls only managed to give away just six penalties, despite being the second-most penalised team in the competition up until last week.

"It's almost a 100 per cent turnaround from being the second-worst to giving six penalties away," he said.

"I can't understand how in one week the Bulls could have turned that around."

Bray and White were due to speak on the phone later on Thursday to review the match, ahead of the Brumbies' last clash in South Africa against the Lions on Saturday morning (AEST).