I want to know first why there was so much concern about Bob not being at home--so much concern that the daughters requested a well-being check, and secondly, why no one in the family went to Bob's house to check on him themselves if there was so much concern.
From all accounts, the daughters had not been around for the previous six months, so they likely had no idea what Bob might have had planned for that day, or why he might have been absent--especially considering the fact that Michaels had just purportedly seen him that morning at the house.
The fact that no one in the family wanted to go check on Bob leaves me scratching my head, as well. From Michaels' account, he obviously had his own key with which to enter Bob's home, so why didn't he go check on Bob himself?
My gut is telling me that an alarm was raised because someone KNEW that Bob was really missing and not coming home again, and that he was not simply at a neighbor's or out for a walk. Further, no one in the family wanted to be the one to enter the home to add more potential evidence to what was likely already a crime scene.