A resident called 911 to report a person wandering around the neighborhood, looking at houses. I have no idea what the details of the call were. The caller probably stated he looked suspicious, and was possibly casing houses. This type of call to a 911 operator mandates a police response.
Police respond to the call, they see Bob Dylan, he matches description the caller supplied. He was doing nothing illegal, and he didn't get all bent out of shape. The officers ask for ID, as that is a requirement when stopping someone. It's for paperwork purposes. Bob Dylan was not legally required to show ID, as he was not under arrest or the subject of a traffic stop. He goes on his way, and the officers make a notation on their paperwork to the effect "subject refused identification".
The officers resume patrol. End of story.