I've read some of the complaints about this novel, ranging from general dissatisfaction with the tiny payoff of the rustling subplot to a very specific confusion over how, exactly, the "fallen man" died. I hope to pinpoint the trouble somewhere between the two.
There seem to be two ways Hal Breedlove could have died, and it is no accident that they hinge on Eldon Demott's accounting for it. If he is lying, then he probably would have stranded his friend on the ledge. That would account for the intact bones. Yet the rock is not so isolated, as even the book suggests, that no one could have heard his cries; moreover it is possible to die from a fall without breaking bones--due to internal injuries, brain damage, etc.
Add to this Elisa Breedlove's recounting of her brother's genuine-looking shock and the weight comes down in favor of Demott's explanation. The author's decision not to break Hal Breedlove's bones, on the other hand, is a little harder to understand. Halfway through the novel people are still qualifying their references to the "so-called" Fallen Man. This appears to allow Leaphorn and Demott to develop their Biblical allusion, my only complaint being that it is done to no purpose. Hillerman has always taken pains to characterize the clash between cultures, Navajo and white, but here he seems to pull back from his own terrain.
Not to put too fine a point on it the Biblical "Fall" is, after all, a choice of knowledge over blissful ignorance, and Lieutenant Leaphorn's private objection, in Chapter 17, to Demott's simplistic analysis hardly constitutes presence of this moral theme. The lack may easily have spilled over, undermining the otherwise vintage resolution of the subplot, both cases only proving what is no mystery: that two negatives don't make a positive.