Why did the six-fingered man leave the sword?

Question

In the film The Princess Bride, when Inigo and the Man in Black have their chat before their duel, the Spaniard tells his adversary about his father and the six-fingered man:

Inigo: My father was slaughtered by a six-fingered man. Was a great sword maker, my father. When the six-fingered man appear and request a special sword, my father took the job. [Draws sword.] He slave a year before he was done. [Hands sword to Man in Black.]
Man In Black: [Admiring the sword.] I've never seen its equal. [Returns sword.]
Inigo: Six-fingered man returned and demanded it, but at one-tenth his promised price. My father refuse. Without a word, the six-fingered man slash him through the heart.

It seems quite clear from this exchange that when Inigo hands his sword to the Man in Black, it's the same sword that his father made for the six-fingered man: hence its relevance to the conversation. But if the six-fingered man killed Domingo Montoya because he wouldn't sell him the sword at a lower price, why on earth did he not take it with him afterwards? The sword was important enough to him to kill a man for it, and yet he didn't keep it after killing that man? It doesn't seem to make sense.

Is there any explanation (e.g. in the source novel) for this apparent contradiction?

Answer 1

In the source novel, Count Rugen claims self-defense to cleanly walk away, and states Inigo's father came at him with a sword and he replied in kind. The sword in question, in fact, that they were actually arguing over.

Not like the villagers would quickly rise up to confront a lord, but they would try to stop him if he didn't at least give a thinly veiled excuse. And such it was, for no one stopped him, even if it was obvious to anyone that knew Domingo Montoya that he wouldn't have attacked. It would have made the lie obvious if he tried to take the sword with him.

The village heard. Twenty men were at the door. The nobleman pushed his way through them. "That man attacked me. See? He holds a sword. He attacked me and I defended myself. Now move from my way."

It was lies, of course, and everyone knew it. But he was a noble so what was there to do?

Of course, Inigo challenges him shortly after, which would give him plenty excuse to take it, but Rugen spares Inigo (stating he's teaching him manners, but possibly cowing the crowd and avoid turning them against him) and Inigo keeps his father's masterwork up until the time of the tale.

Since it's also implied and asked, Rugen kills Domingo mostly out of reaction to his disrespect. Rugen had proclaimed the sword trash and not worth waiting for, after Domingo had worked on it for a year. He also offered 10 gold out of 500, but that was practically icing. Domingo had pride in his work, and he wasn't going to cow to some lord who refused to respect it. He threw Rugen's deposit back in his face, and declared the sword belonged to his son even after Rugen repeatedly insisted he would be leaving with it. He got to three repetitions before he lost his temper (not 'without a word' as Inigo relates in the movie).

It's hard to say if that's really what Rugen thought about the sword or if he was just satisfied with his fear-mongering for the day, since we get no followup on his search for a sword that accounted for his handicap other than Inigo's story. It's likely he tried to retrieve it or commission another but failed at both. Regardless, the main reason for the murder is Rugen couldn't stand to have his own disrespect flung back at him.