Plot hole: It's assumed that Dr. No had Professor Dent slip the spider into Bond's hotel room that night but if it were that easy to do that then why not just hide an assassin in the room to begin with. Someone had to be in the room to tamper with Bond's briefcase, the closet, and possibly the bottle of liquor so just hide an assassin instead of waiting for the spider to kill Bond. (00:40:00)
Plot hole: When Bond, Quarrel and Felix sail to Crab Key, Felix says that it's 48 hours to the moonshot. Bond replies that they'll "Be back in 12, if not then it's your beat and you'd better bring your marines with you". We know that Bond was still on the island when the rocket took off (it's when he kills Dr. No) and yet it's only when He and Honey are sailing AWAY from the island that Felix shows up with the marines. Why did he wait the full 48 hours (longer even as the moonshot had already occurred) when it was obvious something was wrong when Bond hadn't come back after the 12 or so hours as agreed? (00:57:45 - 01:43:40)
Plot hole: When the receptionist is showing Bond and Honey their rooms she opens the closet with clothes for Honey and says they just got their sizes the night before. How? Dr. No's people didn't know about Honey at all until she showed up with Bond, and they weren't even seen together until they were found in the swamp just several minutes before. (01:19:50)
Plot hole: When Bond is escaping through the metal ducts, presumably of Dr No's air-conditioning, he is deluged with torrents of water. He then leaves the pipe work through a metal grille into a passageway - why didn't the water leave the same way? (01:33:05)
Answer: It's obvious what he does between those times. In "Goldfinger," Felix Leiter sees him just moseying off between an event and the climax of the movie and says to his pal "Ten'll get you one it's a drink or a dame." No doubt Bond's using his time...productively.