Apparently you've not heard that home-invaders have taken to wearing windbreakers labeled "POLICE" and announcing themselves as such.
Why didn’t he call 911 if he feared his life and the life of his friend was in danger?
Because when seconds count, the police are just minutes away.
Funny, becuase I used the same argument that was used against Martin. I heard many times that Trayvon should have called 911 if he felt threatened by Zimmerman. Check out all the threads posted at this link.