Character mistake: Miles is playing on the beach a tune that Birdie Jay recognizes instantly as Blackbird by the Beatles, and Miles flexes saying that it's the exact guitar Paul wrote it on. That'd be difficult though, since it's a right handed guitar, and McCartney plays left handed (albeit he can play right handed too). You could argue that this is one of the hints that Miles is not very smart. (00:20:00)
Character mistake: During the dénouement, Benoit Blanc starts "That night, Lionel faxed Andi's email to Miles." But it's established that he faxed it minutes after receiving the mail, which was sent at 4 pm. 4 pm in May, that's hardly 'night'. And it can't be night where Lionel is, since he shows up a little later together with Claire, from Connecticut, at the house of the victim in the New York area. (01:52:25)
Character mistake: In the flashback, Blanc tells Helen that when Miles will pull him aside to explain his presence, that is when it will be her chance to 'snoop'. However, that piece of dialogue is just unnecessarily wrong since the whole distraction with Miles lasts just a few minutes, does not facilitate at all her snooping, and all the other guests are in their rooms just unpacking and hanging out. If anything, Miles keeping the other guests entertained and gathered together is what would facilitate her. (01:25:45)
