Neath chief executive Mike Cuddy aimed a stinging broadside at Munster scrum-half Peter Stringer, who was
yellow-carded during last Saturday's final at the Millennium Stadium.
The Welsh All Blacks retaliated with fury following a six-match ban imposed on their l flanker, but the club have left it too late for any action to be taken against any Munster players.
The rules of the competition state that complaints have to be lodged within 48 hours and passed on from, in this instance, Ireland to Wales within a further 48 hours.
Wales flanker Sinkinson was cited for stamping on Munster outhalf Ronan O'Gara during last Saturday's final, which the Irish side won 37-17.
He was dealt with by Welsh Rugby Union disciplinary chiefs earlier this week and suspended for six weeks.
Stringer received a yellow card from English referee Chris White following a second half stamping incident, and Neath feel Stringer should not be allowed to take part in the Six Nations Championship or April's Heineken Cup quarter-final between Munster and Leicester but that was described as an appalling reaction by Jerry Holland.
"Really, the allegations don't deserve a response. It's so ridiculous to start bringing up tit-for-tat issues.
"We don't go in for this kind of thing and we merely brought a particular incident to the attention of the
"They dealt with it and we can't be held to blame because there was no blame. One of our players was injured and the matter is closed as far as I am concerned."
The Munster team manager also pointed out that Neath should know the rules of participation in the tournament and what's required of them in situations such as this.
"If they were that worried about other incidents in the game, then they should have brought it up within the required time frame. Obviously, they weren't worried at the time."
Neath say they intend supplying video evidence to back up their argument.
Both Munster and the IRFU will receive a copy and Cuddy hopes internal action might be taken against the scrum-half.
He expressed annoyance that Munster had brought up the Sinkinson incident in the first place, even though TV pundit, former English international Jeremy Guscott, described the stamping as deserving of a long suspension.
"We are extremely disappointed that Munster decided to take this course of action, and particularly with the
manner in which they cited our player at the last minute," said Cuddy.
"There were far worse instances than Brett Sinkinson's performed during the match by Munster players.
"We will be compiling a video which will be sent to Munster and the Irish Rugby Union, together with a request that they do the decent thing and give the players highlighted, at the very least, suspensions equivalent to that imposed on Brett.
"In particular, we feel that Peter Stringer should not be allowed to take part in the Six Nations and European Cup quarter-final.
"We did not want to get into a citing battle with Munster, but the manner in which they cited at the last minute was disappointing, to say the least," Cuddy added.
"Relations between Munster and Neath have been soured, and will be even more strained if they do nothing in respect of their players' actions. They must not be seen to condone this behaviour.
"We did not want to pursue these matters further, as we acknowledge that Munster were the better side on the day and it could have looked like sour grapes on our behalf.
"All in all, this matter has left a bitter taste in the mouth."