It was a painful experience for Flood and Tigers team-mates Ben Youngs, Dan Cole, Louis Deacon and Tom Croft but the former Newcastle playmaker believes it could have a positive effect when Leicester take on Leinster at the same venue this Saturday.
"It's a very different animal this time but it's good to go back and, if anything, playing an Irish side there with a similar backline to what was on show last time is a good knowledge to have," said Flood.
"It's good to get back involved and play there again. It's hugely different because it's a club game and it's very different in terms of the emotions that went with what was riding on the result the last time we were there.
"We let ourselves down. You've just got to take that on the chin and move on from it. Those days are more valuable than the days you put 30 or 40 points on teams because you learn a bit more about yourselves.
"Everyone in Ireland had the opinion that they would come out flying and that's what happened really. That's a good learning curve because it's going to be like that at the weekend."
Flood, who hadn't joined the Welford Road ranks when Leicester lost to Leinster in the 2009 Heineken Cup Final, sees plenty of similarities between the Dubliners and their national counterparts.
The 25-year-old is expecting a hugely physical encounter against a side who will throw absolutely everything they have at the reigning English Champions.
But Flood insists that the lessons learnt during his last visit to the Irish capital will stand him in good stead for the size of the challenge that awaits this weekend.
"It was the ferocity of it all really, the aggression Ireland showed, how they behaved and how they went about their work and Leinster are very similar," added Flood.
"Having seen a lot of video this week, Leinster have got the same sort of defensive strategy of holding you up in the tackle and they want to win the collisions.
"We have to be ready for that physical battle because it's going to be a pretty hectic first 25 or 30 minutes.
"That defeat taught us that it's important to try and reign a game back in. It's difficult sometimes as a side to control a game when you're not winning any balance of the ball, you're losing balls in the scrum, you're turning ball over in the lineout and there's a lot of things going on, but you've got to try and just calm it down for 20 minutes or half an hour if that does happen. That's important and sadly we weren't able to do that the last time we were there.
"The guys here are good at that. They have a massive belief in what they're about and what they do. There's a massive trust inside the squad and the coaching staff in what we're trying to achieve.
"That comes out when it comes to game day. You look around the huddle when you're 10 points down at half time like we were against Quins and really struggling to get a foot in the game, but you have this self belief that things will come around."
That win over Harlequins was Leicester's fifth in six Premiership games since the last round of European action but Flood admits nothing short of their best will be good enough to beat Leinster on their own patch.
Joe Schmidt's men have been in superb form since a slow start to the season and with a backline that can boast a whole host of star names, Leicester's general knows stopping the home side at source will be vital to their chances of reaching a seventh semi-final.
"You realise that your level of performance has to be in its top five per cent. It can't be down on that.
"Collision wise you have to win those battles. The big thing for us is to try and make their breakdown as difficult as possible - to slow the ball down, make it a real dog fight because when guys get going like (Brian) O'Driscoll, (Jonny) Sexton and (Gordon) D'Arcy, they look fantastic going forward. It's important for us to really try and stem the flow.
"Sexton links so well with the guys around him. He's a guy who if you let run the game, he can be a huge part in that. If you let him run round the corner, let him throw shapes and throw over the top, then he really comes him into his own.
"The best thing for us is to try and close down his time and space. If we can make it difficult for their nine and 10 to impose themselves on the game then hopefully we can be in a position to cut down the space for their outside backs because they're fantastic."