It would be interesting to know when and where her phone pinged until it was found.
Was the phone on all the time?
Can the pings show she was moving from the home that morning driving here and there? Maybe like driving to an area somewhere she could have gotten mud on her car? (If we believe that piece of rumor.)
Was her phone off from the time she left home (alive or dead) and then magically began to ping before the husband found it?
When was the first attempt made to locate her phone?
If I understand correctly, this is an iPhone we are talking about, so what about GPS coordinates?
These are all things I've thought about so much. I assume LE knows (though if they don't have phone records yet, then maybe not) and I imagine they'd be super helpful to figuring out what happened.
If I were running away, I would turn my phone off before throwing it (if I threw it, which I probably wouldn't). If I was abducting someone, I would turn their phone off before throwing it. The fact that the phone was able to be located where it was implies that it was on when it hit that spot. That makes little sense to me.
iphones famously store a log of your movements (not GPS, cell-tower, so can be off) on your computer every time you back up. So presuming LE have her phone and her computer they can see where she was in the day or two prior to her going missing.
http://ihnatko.com/2011/04/20/hey-wonderful-theres-a-location-tracking-file-on-my-iphone/
The more I think about it, given the fact that she was very attached to her phone, and that they've recovered it, as well as the home computers, hopefully they should have some pretty good ideas about what her movements were that day.