They have now lost four deciders, two semi-finals and a quarter-final since their last success in 2018 when they edged Racing 92 in a tense game at Athletic Bilbao’s San Mames stadium. Add in the failure to claim a URC crown this last three seasons and many of the native are understandably restless with a team that is awash with top Ireland players and one buttressed this term by RG Snyman, Jordie Barrett and Rabah Slimani. There have been plenty of changes in the coaching staff, of playing personnel and even at the top administrative levels since Bilbao but Cullen has been a constant as head coach through all that time. It is only inevitable that questions are now being asked. “Yeah, I think I am,” he said when asked if he was the person to get Leinster over the line again. “Yeah. I believe that I am, yes. I think we've worked hard to try and improve the group year on year on year and I think the group is very strong right now. "As I said, that's not something that's just created last week, it's year on year and I think we've a stronger group now. "We've lost three finals over the last three years, yeah, but I believe we've a stronger group now than we've had and that's the way I will continue to approach the day to day in terms of preparing the short term, medium term, long term. “So, yes. And I'm very committed to that as well.” There is no denying the depth of hurt this 37-34 defeat will generate. Cullen spoke of a loss that will “stick the throats” for a long time. He used the word “horrific” twice and admitted that the game will “haunt” them for some time. His team captain Caelan Doris used the word gutted to sum it all up. As in previous years, they came agonisingly close to getting over the line with Ross Byrne having what would have been the winning try ruled out after a lengthy TMO review in the last minute of the game. The decision may have been that Byrne had illegally grounded the ball while off his feet but the question is why referee Pierre Brousset didn’t then award a penalty try given Josh van der Flier had just been stripped illegally, in the act of scoring, by Alex Coles. Coles was even shown a yellow card for his act. A penalty try seemed to be a given. Instead, Leinster went and ran a tap and go from the penalty with Jack Conan just metres from the line and the clock approaching the red, coughed up the ball and their last chance of the win with it. Cullen neglected to offer an opinion on the non-penalty try decision, claiming he was concentrating on the next play at the time, but replacement prop Rabah Slimani admitted that the failure to award seven points to Leinster was puzzling. “I don’t know, I don’t know,” said the French front row. “I don’t understand the decision because if it’s a penalty and a yellow card I don’t know why it’s not a try, but that’s the ref’s decision. He has his opinion but it’s hard.” Northampton’s director of rugby Phil Dowson was asked for his take. “The thing that was going through my head was that if they score here, it feels cruel. I know sport's cruel and I know sport's unfair, and that's the beauty of it, but to be leading - I think we led the whole game, I don't know. “To have lost it in the last minute with a bobbled ball and a referee's decision. Was it a knock on? Did Colesy release? It's all very intricate and subjective, and the referee makes a decision there and if we'd lost that I would have been gutted for the players.” So many questions, so many talking points. Leinster could still have kicked for the posts in the last act, taken three points and reset for 20 minutes of extra-time. Cullen didn’t have any issue with going for broke, backing his players to go with their gut when push came to shove. Ultimately, they didn’t play well enough. A team that hadn’t conceded a single score in 200 minutes of Champions Cup rugby prior to this leaked five tries despite having Jacques Nienaber, the most respected defensive mind in the game, sitting in their coaches’ box. And, as good as Northampton were, and as impressive as players like Fin Smith, Henry Pollock and hat-trick hero Tommy Freeman were, this was still a side sitting seventh in a Premiership of debatable worth. “There's definitely a strong feeling among our group that we haven't done ourselves fully justice,” said Cullen. “What's the reason for that? That's the great mystery, isn't it? A couple of things weren't just quite accurate, we had a tonne of opportunities but just didn't quite deliver. “But then you can get a little bit jittery. Saying all that, the last four or five minutes of the game, we're camped on their tryline and we just don't have the composure to get over the line. "That's the painful learning for us. There's nothing we can do about it.”