I think Poirot had maybe a couple clunkers in his answers, but Lucifer seemed sort of resigned to getting an anti-Poirot vote more than pro-Lucifer, so I think Poirot probably will have this? We'll see with the closing statements. I think Lucifer completely punting on Grouch's question about how the jury will vote (which, I'll be honest, I always hate as a question, it feels like such a trap, but kudos to Poirot for stepping up on that one and actually doing a good job) probably pushed Grouch towards Poirot a bit.
I think Poirot's biggest missteps were probably towards Pikachu, e.g. saying that when Pikachu tried to push me/Poirot/Judy as a vote it "backfired" on him, which I think was poor phrasing; it didn't get any traction, but Pikachu basically got the votes the way he wanted them on that vote, he just got hit with an idol, which I suppose you could ascribe to him targeting Jake and Jake's allies in the former SVU. I probably would have gone out of my way to frame that vote as like "hey, Pikachu, you made a great move that should have worked, I was fortunate enough to be good with the person you targeted and he had an idol". I understand the point that Poirot was making, which wasn't about how Pikachu went home that round but how a vote on Poirot couldn't have happened, but it seemed tone-deaf to me. Pikachu later seemed to strongly imply that he would be voting against Poirot for other reasons, so maybe it was a lost cause entirely, but I don't think that helped.
On a tangentially related note, one thing I've never been crazy about is when jurors criticize finalists' jury management of other players. Like, if A manages B poorly, then B doesn't vote for A, that's the consequence for that in my mind. I have a hard time imagining myself holding it against someone who I liked and felt treated me well for managing some other juror poorly (outside of serious social transgressions that go beyond "jury management", like sexism/racism/whatever). I realize that part of the game is understanding the criteria that each person uses in their evaluation of who to vote for at the end, so if someone's jury vote hinges on your jury management of everyone else then you're obligated to take that into account, but that's a criterion I've never been crazy about people putting much weight into.