Revealing mistake: When Bond sends an assassin crashing into the tank containing the octopus, you can see the assassin is a dummy.
Other mistake: When Bond jumps onto the coupling of the horse-trailer, you can see that the idler wheel is already on the ground. It would be crazy to drive around a rough surface like near the racetrack with the idler wheel down - the trailer could be overturned. (00:04:50)
Plot hole: When the saw yo-yo comes down for the third time, Bond grabs the cord to pull the wielder down off the gallery. That was, when you think about it, a patently bad idea. If the yo-yo hadn't become stuck in the desk, Bond would be collecting his fingers in his hat (note that the blades are still spinning as Bond grabs). (01:15:45)
Other mistake: When Bond starts up his plane during the pre-credit chase scene, the Cuban forces are visible at the horizon closing fast - they have to be to keep the tension up - but with the closing speed and the time it takes for Bond to roll out his plane, there would never be enough street left for him to get airborne.Doc
Factual error: In the forest, Bond runs into a giant spider web. First, the spider's thread is far too thick and resistant. No cobweb could slow a person down. Second, there are several spiders hanging in the same web. Spiders don't share their nets with others. Third, these spiders are supposed to look like tarantulas, which don't spin webs. (00:59:30)
Revealing mistake: When Bond falls off the train the scenery switches from outdoor filming to an obvious film set.
Continuity mistake: When Bond is pinned to the wooden door by the knives we see each knife cut his shirt, trapping him to the door, but when he opens the door and grabs the knife with his left hand, his left arm is now completely free, with no holes or rips on his sleeve.