As I recall, the Sheriff took a question about the keys and said they were found on the trail between JG and EC.
Could be possible EC set out for help/the car and didn't take the keys and in his dehydrated state JG threw them towards her (unknowingly to EC) and is why they were found on trail between the two. Imo
Such a tragedy. I think they set out for a fun day of hiking with just enough water.. (obviously they didn't think the amount was an issue). I have done this many times dressed same as they were, and never even thought about having to survive anything. Mainly because I'm not an experienced hiker. Sadly they are no longer able to learn from their mistakes. RIP