Michael Cheika questioned why New Zealand's Ben O'Keeffe had been appointed to referee an English Premiership rugby match after his Leicester side lost 38-31 away to Gloucester on Saturday.
O'Keeffe is due to oversee reigning Six Nations champions Ireland's tournament opener at home to England in Dublin a week on Saturday but veteran Australian coach Cheika was far from pleased by his involvement at Kingsholm, with the former Wallabies and Pumas boss adamant the Tigers "deserved more than we got out of that game".
"I am not going to have a go at anyone, but I am not sure why they are bringing in the international referees this weekend," Cheika, 57, told TNT Sports.
"I didn't like it from the start, when they said it was happening. It is clear there is a difference in interpretation in how the ball is played on the ground.
"We got affected by the penalty flow, and we have got to be better to resist those moments when they come, even if they are numerous."
Leicester, who suffered a humiliating 80-12 loss away to holders Toulouse in the European Champions Cup last weekend, contributed hugely to a game of nine tries.
The match was decided by a third quarter when Gloucester, who are winning plaudits for their attacking game, scored 21 unanswered points.
Argentina fly-half Santiago Carreras enjoyed a match haul of 18 points, including a try, for the Cherry and Whites. Wales scrum-half Tomos Williams, Scotland centre Chris Harris, hooker Seb Blake and flanker Jack Clement also crossed Leicester's line.
Victory lifted Gloucester into third in the table, a place above Leicester. The top four at the end of the regular season contest the title-deciding play-offs.
"We have got to be real about the challenge, but with the rugby we are putting on the field we are capable of winning the Premiership," insisted Gloucester boss George Skivington.
In Saturday's other Premiership match, Exeter record only their second league win of the season as they beat Saracens 31-22.
Saracens, without a raft of players due to injuries and Six Nations call-ups, including new England captain Maro Itoje, led early on but lost lock Harry Wilson to a red card eight minutes from time as they missed a chance to go second in the table, behind Bath.
Exeter outscored Saracens four tries to three, with Jack Innard, Will Rigg, Tommy Wyatt and Ethan Roots all touching down for the southwest side.