Sam Falco said:
Its not awful writing, Mac had accepted the fact that he was a traitorous ******* who was getting what he deserved. His reassuring last words to Indy was meant so that Indy wouldnt keep trying to save him, thus getting himself killed in the process.
I agree that this is what the movie was trying to convey, but it did so incredibly poorly. Whether the blame lay in the writing, directing, or editing, I think it should have been handled better. First off, I don't like how Mac falls. In the movie, it looks like he just falls down because of a sudden tremor that the temple makes, and that all he has to do is just get up. I didn't see any evidence of him being "pulled" away until after he delivers his last line. I mean, it seriously looks like he's just lying on his stomach because he's too lazy to get up.
In the various novelizations and the comic book, it's made much more clear that the magnetic force is pulling Mac back because of all the loot and gold he's stuffed in his pockets. Also, we're told that Mac intentionally lets go to save Indy and the others, and because he recognizes that he's not worth saving. For whatever reason the movie opts to make it much more confusing and sloppy. Mac should have been visibly being sucked back from the moment he falls over, and we should have been given a clear shot of Mac
voluntarily letting go of the whip. It probably would have also helped if a moment was taken to show Mac's deliberation, instead him suddenly changing his attitude out of nowhere. As it is, his saying, "Jonesy, I'm gonna be alright" was the biggest WTF moment of the film.