Well, knowing that Dylan used to experiment with interesting mind altering compounds, if he was "acting strangely", what would you have the cops do? Ignore the call?
We sit here and criticize the police for investigating a potential problem. Suppose that it was your father or mother who walked away from their retirement home? Do we blow that off? No, in today's world, the police would be negligent for doing so. Due diligence is the new catch-on for law enforcement. We have become the arbitrators for all societal concerns. We no longer have the luxury of just preventing crime. We are now mental health workers, babysitters, marriage counselors, etc, etc.
Whether or not you agree with those duties, it appears society wants, and demands, that from us. Should we not attempt to address those issues the results are mega-dollar lawsuits.