London - Wasps formally expressed their disappointment on Monday over the refereeing blunder that saw them beaten 20-18 by Connacht in the European Champions Cup at the weekend.
Substitute referee Mathieu Raynal erroneously allowed Connacht to take a line-out after kicking to touch from a penalty awarded on full-time, from which the Irish province scored a decisive converted try.
Competition organisers European Professional Club Rugby (EPCR) admitted Raynal had made an error after the match, but allowed the result to stand.
"We all understand referees are only human and mistakes do occasionally happen," Wasps said in a statement.
"However, for a referee and fourth official to get the laws of the game wrong at a crucial stage of a big match is hugely disappointing.
"The error made could have serious repercussions in terms of Wasps' qualification hopes or the prospect of securing a home quarter-final."
Raynal took over in the 74th minute at Galway's Sportsground on Saturday, having started the match as an assistant, when referee Jerome Garces suffered a hamstring injury.
It is thought Connacht captain John Muldoon told Raynal his team were allowed to kick for touch from the penalty and then take a line-out despite it being in overtime.
But a trial permitting that rule change does not come into force until January 1 in the southern hemisphere and August 1 in the north.
Naulia Dawai crossed from the line-out before Jack Carty's conversion secured a victory that left Connacht level with Wasps and Toulouse on 13 points in Pool Two.
"Wasps' pitch-side officials immediately stressed to the fourth official that Connacht could not take the line-out, as the referee had indicated time had gone beyond 80 minutes," Wasps added.
"Wasps' players on the pitch also emphasised to the referee that time was up. Despite several protests, the line-out was still allowed to be taken.
"EPCR have stated that the result stands. We congratulate Connacht after a hard-fought contest and we will now move on to the final rounds, after tough Premiership games against Bath, Newcastle and Leicester Tigers."