When I try to think logically about the information and evidence we've been given, my thoughts go to the possibility that Zahra died/was murdered when she was up and awake and her prosthetic was in place.
Looking at the photos of the home where evidence was removed, that leads me to believe that she may have been struck in her bedroom, on or near her bed. Sometimes it just takes one blow, aimed at just the right spot, to kill a person. And of course if something is being used to strike someone, well the odds increase considerably. Multiple blows would have the same disastrous effect.
So if she was home alone with EB and they were fighting, or EB was "punishing her" for something, I would think that the place she would flee to get away from the violence/rage/anger is her bedroom. And with someone angry and in a rage chasing her in there...who knows. Especially if Zahra dared to run away from a "punishment".
The reason I think she was wearing the prosthetic is because it was disposed of along with her remains. And the location where at least a portion of it was found, the gel liner, also gave up a large bone belonging to Zahra. If the prosthetic was in place at the time of her death and someone had tried to remove it after the fact, would that gel liner stay in place? Would it be more difficult, perhaps with bloating, to remove? Do the prosthetics basically come in separate pieces? Perhaps Allusonz can weigh in on that.
I'm beginning to think that the piece of evidence that EB's lawyers turned over to police might have been the rest of the prosthetic which was disposed of in the third location (possibly Indian Grave Rd) and that LE only actually found the liner at the Christy Rd site. If that leg had been dismembered, then the bone that was found was likely the femur...probably displaced by animals.
As always JMHO and please shoot the holes in this theory because it's just too awful to comtemplate. I much prefer the died of natural causes peacefully in her sleep version.