RC, of course you have a point, not sure what I would do. But I think there are several escalating stages. Starting with, a routine call to police about a suspicious person in relation to the security of the neighborhood. GZ realized TM saw him, thus making it personal to GZ safety. Even though at that point he became fearful, he still had the police on the phone and knew they were on their way, giving him some courage. He then exited the vehicle hoping to keep track of him.
I agree.