Brumbies coach Dan McKellar has suggested Super Rugby officials are not following the strict red card precedent set at the World Cup last year.
The Brumbies lost 23-22 against the Highlanders on Saturday night and winger Sio Tomkinson was lucky to escape being sent off for a dangerous tackle in the second half.
He has since been referred to the SANZAAR judiciary with the tackle deemed to have met the red-card threshold for foul play.
Tomkinson didn't wrap his arms as his shoulder hit Brumbies fullback Tom Banks' head but referee Nic Berry deemed the initial contact was shoulder to shoulder and opted for a yellow card.
The replays looked ugly but Banks was able to continue playing.
World Rugby vowed to protect players at the 2019 World Cup and a record eight red cards were brandished - more than the past four tournaments combined.
Berry sent off Ireland's Bundee Aki for a dangerous tackle at the World Cup but the whistle-blower was in a more forgiving mood at Canberra Stadium.
McKellar didn't blame the decision for the loss but believes Tomkinson should have been sent.
"I thought it was a red card," McKellar said.
"If you're asking me as a rugby fan, I thought, from what we've seen previously, I thought it was in that red card threshold."
Even Highlanders coach Aaron Mauger conceded by the letter of the law his winger's night could have been over.
"It's a tough one, isn't it," Mauger said.
"If you're reffing to the letter it's contact with the head, but I don't think there was any malice there and there's nowhere for him to go.
"It's one of those ones that happens in a split second, so I don't think there was any chance of pulling out."
The Brumbies were kept scoreless in the 10 minutes Tomkinson was off the field.
Conversely, when Brumbies lock Murray Douglas was sin-binned in the 80th minute for repeated infringements the Highlanders were able to score the winning try after the siren.