Perhaps his son could clear things up, since Chad used him to support his claims on the call:
"She was physically falling apart. She hates doctors... My son G was with me the whole time... "
https://www.fox13now.com/news/local-news/chad-daybell-bound-for-trial-in-district-court
Im guessing if charges come about for Tammy's death there will be testimony from Chads kids about the state of their mother prior to her death. It would be damning evidence against Chad if his children did not corroborate his story.