But, just like Clermont colleague Julien Malzieu, Hines feels his side could eventually be better for the experience as they target Top 14 glory and future European domination.
"We've evolved a little bit more. We have to learn from this and realise that it's okay to play well but you can't make mistakes otherwise you get punished," said Hines.
"We need to do that in a month's time and take that into the Top 14 semi-final. If we can do that, I'll be happy. I'm not happy now, but I just hope some good can come out of this loss."
Hines was a Heineken Cup winner with Leinster last season and the Scotland second row therefore knows the men in blue better than most.
He admits he was always wary that Leinster would produce something special - just as they did with Cian Healy's superb score just two minutes after the interval - but the manner in which Clermont had performed in the opening half had left him quietly confident they could pull off one of the biggest wins in their proud history.
Healy's converted try and the Jonny Sexton penalty that followed shortly after dramatically changed the course of the game, though, forcing Clermont on to the back foot when the French outfit were already battling against a troublesome headwind.
"We're gutted. I thought we played some really good footy but then they scored that try early in the second half," added Hines.
"I knew they had that in the bag but I didn't see it coming. They then got a penalty shortly after that that.
"That was a 10-point lead, they had the wind, and Jonny (Sexton) was always going to put in down in our half and we were always going to find it hard to get out. When we did get out, we didn't do too badly but we couldn't get out enough.
"We only got out in the end because of a penalty, and I don't think we got too many penalties in the second half. That's one of Leinster's strengths: they don't give away too many penalties. When you're camped in your own half, you're not going to get a piggy back ride out.
"We could have won that game. There's no excuses. We just didn't defend well enough just after half time."