Town boss Nathan Jones was left aggrieved by the decision from referee Andy Woolmer not to send off Peterborough defender Mark Beevers at the weekend.
Midway through the second period and with the Hatters leading 1-0, the Posh captain clearly handled when the last man as Elijah Adebayo looked to skip around him and race through on goal.
Although whistling for a free kick, Woolmer then somehow opted to just produce a yellow card, a call that baffled those on the pitch, in the dug-out and the stands as well.
Shortly afterwards, the Hatters did have a second goal though, Harry Cornick turning home and then Fred Onyedinma immediately making it 3-0, but Jones was still annoyed by the ruling at the final whistle, as he said: “It was the wrong decision for me, that’s all, people make errors and so on, but that was a wrong decision.
“He’s the last man, he’s knocked it round him, he’s handballed it, if he brings him down, he’s just stopped a goalscoring opportunity.
"He’s clean through, there was no-one else around him, so it’s a wrong decision, it’s a red card.
"It didn’t affect the result, but it could have and that’s the thing.
"At the time it was 1-0, and we scored straight after which kind of softened the blow a bit, but you’ve got to get those decisions right and that wasn’t a difficult one.”
Once Woolmer had made his mind up, he was then called over to the dug-out and ended up dishing out cards to both managers on the advice of the fourth official.
When pressed about what went on, Jones added: “It’s the Championship and I don’t know what the fourth official was doing as I get on with the fourth official, he’s a lovely guy.
"I don’t know why he did it as we didn’t use foul language, we might have been a bit vociferous, but it’s a Championship football game, what do they expect?
"It’s not kindergarten, it’s not Glastonbury, it’s a Championship football game.
"I’m puzzled by that, but it won’t take the shine off what was a fantastic game.
“It wasn’t between me and Darren, the fourth official just thought we were a little bit aggressive in what we did, but he could have sorted that out easily, said 'look, calm down, I don’t want to see that again,' fine.
"A yellow card’s easy, I had the same thing as what Beevers had, and Beevers' denied a goalscoring opportunity.
“Me and Darren get on, I like Darren, no bad language, it was probably just a bit vociferous towards the fourth official.”