He couldn't ID him so he went to talk to him...and do you know he doesn't stop every person he doesn't recognize?
And if T refused to acknowledge Z talking to him or became agitated because some creepy strange dude coming up to him and continued walking, Z should have backed off. He can call the cops if he wanted to but that would have ended it.
Big difference between being responsible and being a hothead.
BTW if I took Z's call I would ask the following...
Me: what is the person doing that is suspicious?
Z: they are walking down the street in our gated community and I don't know who they are.
Me: do you know everyone in the community?
Z: yes
Me: does your community allow visitors?
Z: yes
Me: are the visitors required to be registered?
Z: no (because I don't know any gated communities that does this)
Me: what makes the visitor or their behavior suspicious?
Z: he looks like a criminal
Me: why do you say that?
We are now down to nothing other then T being black.