fgqb#19nyj said:

I'm sure he would have just easily used the Force to float it back to him. It's not like he couldn't, or wouldn't do that, especially in the situation he was in.

I disagree. You HAVE found a continuity error here, no-one is disputing that. But I think if faced with the choice of correcting it either by editing it back into the scene where it is missing, or editing it out of the scene that creates the error in the first place......I think it far more compelling for Luke to throw it away and basically say to himself "I won't be needing that again". Film 6 is the end of SW....so what resonates in the mind more? A happy picture perfect ending with our heroes (and the audience) sure of their place in the world. Or Luke saying to himself (and to us, through his actions) "I'll have no further use for this lightsaber"? Is he giving up being a Jedi? Is he planning on becoming more spiritual and wise...like his former teacher Yoda...thereby not really needing a lightsaber? Its open ended in a way that stimulates the imagination, rather than wrapping everything up nicely and spelling it all out for us. Thats just my view though...