Rarely has a game at Franklin's Gardens had such a controversial finish. With Saints pressing for a last-gasp try that would have put them within grasp of a spectacular come-from-behind win Manu Tuilagi put the ball dead close to the Leicester line.
With several seconds left on the clock the home pack gathered themselves for a final call, only for referee Wayne Barnes to blow for full-time.
Mallinder is renowned for his reserved nature on the touchline, but there was plenty of emotion at the final whistle, and he explained to BT Sport why.
"I thought that there were 10-to-15 seconds left," he said. "The ball went out, their physio did well slowing it down and holding it while Ben Foden was trying to get it, and there seemed to be time on the clock.
"Our lads were calling the lineout, and we were very disappointed not to get the chance to throw it."
While the hosts finished the game strongly it was Leicester who had the best of the first half, dominating position and territory and scoring a deserved try through Anthony Allen.
However despite pounding away the visitors could not find another way through the Saints' defence, instead relying on the boot of Owen Williams to keep the score board ticking over.
"Leicester had a good start and in the first half they dominated," Mallinder continued. "But we came back into the game and scored the try towards the end of the first half. Then we got a bit of momentum playing down the slope. What we didn't do was exit our half very well, and we let them kick a few penalties, and fair play to Owen Williams, he kicked everything.
"So we've got to look at ourselves in that field position and improve in that area. But I thought we finished well and put them under pressure. They were struggling and had a couple of yellow cards, and it just didn't go our way in the end."
There will be a couple of consolations to take into the final four games of the Aviva Premiership campaign. For one thing, the Saints scored two tries to Leicester's one - Kahn Fotuali'i scoring late in the first half and Ethan Waller crossing five minutes from time.
And despite losing to Leicester there are still five points between the Saints and the third-placed Tigers in the table.
"It's tough against Leicester," the Saints boss added. "You've got to be accurate and we weren't quite as accurate as we needed to be. But I think we showed signs today, we will get better and we're still second in the table with four games to play.
"We're upset we've lost a local derby but we're still in a good position."
There are just two regular season home games left in the 2013/14 Aviva Premiership campaign for the Saints to secure that second-placed finish, and you can do your bit by packing the stands for the capital clashes against London Irish (April 20th) and London Wasps (May 10th).
To book your tickets just CLICK HERE and follow the straightforward instructions, whether you're using a desktop, laptop, tablet or smartphone.
