From what I know it isn't the family who has been accusatory or pressing towards the vff.
That IMO has been the social media sleuths that won't accept his and his family's varying explanations.
Kent and Lisa Landry just want to bring their boy home and allow him to rest peacefully. They have excepted that Jason is in heaven and believe that he is no longer alive. I've seen Pastor Landry on media interviews say that is their top priority. Answering questions and figuring out how he passed would come later and the family trusts investigators to handle that aspect.
Project Absentia is a San Antonio, TX based non profit organization dedicated to Missing Persons operated by a former FBI agent,
A. Mark Pena licensed PI. The organization volunteered to assist the Landry family and have been on board from the very beginning. Their goal is to assist families, as a go between if you will, and LEO. That is where the polygraph test was administered and deemed the vff to be honest on all questions asked during the test.
I am of the same belief as you as to what happened to Jason. The only thing I can't accept is that his body is simply not out there.