The friend who found them (Aug 18th) stated that Kylen’s father screamed at her to return to her car for her own safety and she thought “it’s silly to think the killer would still there four days later.” Link at end. It sounds like the father & friend believe they were killed Aug 14/15, which accords with the Aug 15 obituary date.
It’s not uncommon for obituary writers in these situations to pick a death date - the date the person went missing, the date the person was discovered, etc. Abby & Libby have different dates in their obituaries, for example. And obviously Crystal’s obituary omits her marriage. It’s up to the writer, and the obituary doesn’t need to be accurate or complete.
My guess is that Kylen’s family picked day they believe she died and Crystal’s picked the day of discovery. I haven’t seen anything to suggest that Crystal died on the 18th or that they died on different days - correct me please
Footage Shows Last Time Slain Camping Couple Seen Alive
JMO