OK, it does seem odd that the son in law would leave without having made sure that Bob had returned from wherever he had gone. The above video, shot the day after he disappeared, states he could not walk more than two blocks and showed early signs of dementia. I have to go back to the timeline, but SIL leaves at some point to go to the hardware store, returns a few hours later and then leaves again with no sign of Bob. But he assumed that Bob was visiting with a neighbor for several hours. I am certain that the name of that neighbor was somewhere in the investigation...but neighbors state they had not seen Bob since Saturday.
Fontelle spoke with Bob Sunday night-who was the last non family member to speak with him after Sunday-the cleaning lady? See, I was going to state that she would have been in a unique position to see if things had been altered in the house, but the point of the SIL being at Bob's house was for him to have been moving furniture around in preparation for the arrival of Fontelle, correct?
So things would have been moved around anyway.