We don't know that they attempted the whole loop. Many have speculated that they entered from the other entrance, a mile and a half from where they parked.
LE said they "thought" they planned to hike the loop, based on their tracks, but they never confirmed that. As I've said before, this is what they said at the beginning of the investigation and we don't know what they've learned since then.
I was not clear what you meant and that's why I asked.
I still think it's possible that they intended to be out for a few hours and be back by 11:00 or so, before the hottest part of the day, based on the amount of water they had and the fact they apparently did not die from dehydration.
I have no doubt LE is investigating thoroughly, which is probably why they are waiting for the final autopsy report. They want to provide answers for their family and sometimes that takes time.
IMO