Leinster Coach Michael Cheika has warned his side that unless they tighten up on their discipline they won't be hanging on to the Heineken Cup.
"When the players came into the dressing room after the game they weren't in a celebratory mood because they realised their ill-discipline could have cost them a Heineken Cup semi final place," admitted Cheika.
"We just hung in there and tried to edge back in front. It was very similar to last year."
"With the ball in hand we played well but our discipline simply wasn't good enough."
"We have to face up to the fact that that kind of discipline won't be good enough to win the Heineken Cup."
"They put us under a lot of pressure and I had prepared myself for a close match. But I didn't think it was going to be that close, going down to the very last kick of the game."
While Cheika was pleased to see his side reach the last four with a 29-28 home win over ASM Clermont Auvergne, he was realistic enough to understand his team would have lost had Brock James brought his kicking boots.
"But that's where our experience in this competition is helping us, we came back twice against the team that I believe is going to go on and win to Cup 14 in France."
"We know that Brock James missed a lot of kicks and that if he had been on the mark we would have lost the game. We were challenged by a quality team and we just got over the line."
James ended an horrendous night with his usually trusty boot by missing a drop goal attempt from 25 metres that would have won the game with the last kick of the match.
That was his third miss in the drop goal stakes and he also missed with five goal kicks. That led to a brutally honest assessment of his night's work.
"I was rubbish tonight - it was just one of those things. I don't know what got into me," admitted James.
"I just wasn't good enough and it is so disappointing because we had the opportunity to win the game.
"We got ourselves ahead, but then out of the game and didn't keep our hands on t5he ball."
"Leinster capitalised on our mistakes that we always knew that if we played our game we were going to be in with a chance of winning."
"We really wanted to go to the next stage in this tournament but now I guess we'll have to go back to turn our attentions to the Top 14 - it's all we've got left to play for."
Clermont backs coach Joe Schmidt, who will take over from Cheika as Leinster's head coach next season, said he had not lost faith in James and had been happy for him to carry on with the kicking duties.
"We played really well at stages and that's why we're so disappointed," said Schmidt; " Brock has been our kicker for the past four years and I still have a lot of confident in him. He missed a few, then picked up a couple and we hoped that that would put him back on target."
"But it wasn't to be but I still thanked him for his efforts in the dressing room afterwards and told him to look after himself and get sorted out for next week."