Saints boss Jim Mallinder branded the decision to disallow his side a try in the defeat to Harlequins ‘ridiculous’.
Mallinder’s men went down to an 18-9 defeat at Franklin’s Gardens as Nick Evans kicked six penalties for the English champions.
But Saints were left scratching their heads as Ben Foden’s first-half score was pulled back for a forward pass.
Referee Wayne Barnes trusted his touch judge and could not refer the decision to the TMO as he had already blown his whistle.
And Mallinder was left bemused by the series of events which was to cost his side dear as they slipped to fifth in the Aviva Premiership table.
“It’s ridiculous,” said the Saints boss. “Why have technology and not use it? It’s ridiculous.
“The players did ask why and apparently because he’s called a forward pass you then don’t go upstairs. Once the whistle’s gone they can’t go back.”
Barnes’ decision compounded a difficult day for Saints as they could only register through three penalties.
And Mallinder, though disappointed with the try that never was, admits his men made their own mistakes, which cost them the game.
“Of course you’d love to get five, maybe seven, points from that and it could be different,” he said.
“But you’ve got to crack on, those things happen and we’ve got to look at our parts of the game that we didn’t get right today and they did.”
Harlequins were down to 14 men midway through the second half as James Johnston saw yellow.
But the away side won that period 6-3 and it was to prove pivotal as Evans booted Saints out of the game.
“It was a close game,” said Mallinder. “We talked about the conditions being very influential and they were.
“We got to 60 minutes at 6-6 and they went down to 14 men and that was really the time for us to press on but we didn’t.
“We made a couple of crucial mistakes and a lot of credit to Harlequins for closing the game out.”