> As Keefe began to shoot video, the installer saw him and immediately packed up his equipment and drove away, so Keefe also returned to his car and followed several cars behind, hoping to document the next stop.
Not to say the installer wouldn't have anyway, but it's not inherently unreasonable to call 911 when someone is obviously following you.
It is unreasonable, because 911 is for emergencies where life or property is imminently threatened.
If you believe someone is watching and following you, then you can call the non-emergency number. Or your mom.
They can also drive to a police/fire station