Scarlets coach Simon Easterby admitted there were too many errors in his side's game after the region went down 20-13 to defending champions Leinster in the Heineken Cup.
Successive defeats have left the Scarlets all but out of Pool Five, with Leinster and Clermont Auvergne now the two favourites to get into the last eight.
Easterby said: "It was difficult to take. Ultimately there was a lot of error count in our game and when you play a team like Leinster you have got to make sure your error count is low and you get a lot right in your game."
He added: "In the first half they won the battle of the breakdown definitely. We had a chat about that at half-time and we knew going into the game the way Greg Garner referees. He doesn't give many tackles for the attacker assist releasing. So we hold our hands up there and we got that badly wrong.
"But no excuse - we got what we deserved in the first half. I thought at 11-0 down we were starting to chase the game but we had a chat and came back with a couple of scores. We made a few changes."
Leinster head coach Joe Schmidt was delighted with the win and especially his side's defensive display.
However, he also credited the Scarlets' resolve in coming back from 14-0 down to secure a losing bonus point.
Schmidt said: "We performed really well and really love to put a really good performance together.
"We did put in a really good defensive performance together and to contain the sort of armoury the Scarlets can throw at you - we were delighted to keep them scoreless for so long.
"They had some really good moments of pressure but we managed to keep them off the line."