Plus, you've got the severe question of whether a guy holding a knife at your throat is your "neighbor". Lying to the devil or his authorized representatives, is morally OK by me.
You know, I have really been thinking about this as it pertains to possible future events for us as Christians. In Hebrews we read that the just shall live by faith. Denying our faith is denying what sustains us.
I don't claim to know what is transpiring between this man and God. I pray that he will be as Peter. Remorseful yet filled with such a love and zeal for Christ that he spends the rest of his life evangelizing or what have you.
And if this "neighbor" holding the knife were to repent and give his live to Jesus, he to would be saved and have eternal life. If God will give eternal life to this guy, I'm sure he will forgive the victim for his transgression. Thats the whole point of grace, NO ONE is without sin, and only by God's grace can we be saved.