Continuity mistake: After Montoya has hauled Wesley to the top of the cliff, he drops the rope on the ground, where it lands forming a couple of coils. You can see this as Wesley sits down and Montoya leans up against the wall. However, when they start their duel, the rope is hanging straight off the cliff, without any coils in it.
Continuity mistake: When Westley and Inigo are duelling, Westley flings his sword so that it sticks into the ground and then athletically flips from a bar to where the sword is and nonchalantly reaches down and back and takes it out of the ground. But if you watch, he lands too far away from the sword to do this.
Continuity mistake: When Vizzini is cutting the rope at the top of the cliffs of insanity he cuts it really close to the rock the rope is wound around. In the following shots there is a lot of length of rope between the rock and where it was cut.
Continuity mistake: When Westley and Buttercup are walking through the Fire Swamp Westley's hair continually gets better or changes. One scene it is slicked back and another it is in his face or over to one side, etc.
Continuity mistake: After Fezzik has finished dunking Inigo's head in the bucket of water, Inigo has hair stuck across his forehead. While talking to Fezzik Inigo's hair suddenly is all brushed away from his face. Inigo's hair changes back and forth throughout the rest of the scene.
Continuity mistake: After the grandfather has finished reading the book, he stands up to put on his hat and coat. The shot goes to behind him, and we see that he has already put his left arm through the sleeve. Then the shot changes again and we see him from the front as he is sliding his left arm into the sleeve.
Continuity mistake: When Inigo and Count Rugen are duelling in the banquet room, watch the Count's sword: after he stabs Inigo near each shoulder and draws out the sword it is clean. A moment later, as Inigo falls forward a bit and then rights himself, blood is seen on the Count's sword. If you watch both their swords during this entire scene you'll see the disappearing/reappearing blood.
Continuity mistake: When Fezzik falls to the ground after fighting with Westley, there is a very large rock right next to him. However, when Westley tries to roll over Fezzik, the large rock is too close to do so. Therefore, the next shot shows them further away from the rock so Fezzik can be rolled over.
Continuity mistake: During the scenes when Buttercup wears a red dress (from horseback ride to Fire Swamp), watch her legs carefully. She is wearing red stockings which periodically disappear and reappear.
Continuity mistake: In the scene where Inigo kills all of Count Rugen's guards, notice the position of the dead guard in front of Fezzik and Westley. He changes position once after the shot of Count Rugen running away, and again when Fezzik puts Westley on the suit of armour.
Continuity mistake: When Inigo is lying aginst the wall after Count Rugen has stabbed him in both shoulders, back shots of him show his head is tilted to the left and bobbing while in front shots, he is holding it straight.
Continuity mistake: There is a scene where Westley is matching wits with Vizzini. In every shot of Vizzini and Buttercup, her hair changes. In one shot, half of it is over her shoulder; in the next shot it is all down her back. This happens all through the scene.
Continuity mistake: During the first scene when the grandfather is reading to the grandson, he opens the book. When he gets his glasses the book is shut and he has to open it again.
Continuity mistake: When Buttercup and Wesley are rolling down the hill, Wesley's hair is flying all over and is quite long. When he stops, his hair is slicked back and in a pony tail.
Continuity mistake: In the scene where Fezzik, Inigo, and Westley are on the wall after Westley is tortured, Westley's hand changes position several times throughout the scene. This is odd considering he can barely move his thumb. But it changes between at least three positions several times.
Continuity mistake: Watch the red car behind Fred Savage in the bedroom. In close shots, the car is pointing towards the camera. In wide shots it's pointing sideways.
Continuity mistake: Fezzik tries to crush Westley on a boulder. We see him doing the crushing spread-eagled, but when the angle changes to a close-up, he is holding Westley's wrists tightly under his chin.
Continuity mistake: When the Albino is cleaning Wesley's wound in the Pit of Despair, watch the rag: it goes from white to deep red and back to white between shots.
Continuity mistake: At the beginning when Buttercup tells Westley to fill her buckets with water, her hair goes from being all over one shoulder in her closeup, to hanging down her back as she walks away. When she turns around, it's all over her shoulder again.
Continuity mistake: When Buttercup's kidnappers are arguing over whether or not they should kill her the weather goes from overcast to sunny and back again within a few seconds.
Answer: Westley comes back from the sea, only to find that his one true love is engaged to another man. He feels her love for him wasn't true if she could even think of getting married again, at least so soon.
Brian Katcher