IF there was a first verbal exchange, I'm picturing it as having to take place 10 to 180 seconds before the recorded call to dispatch starts. Quick contact, Z is suspicious, TM stays in visual range, Z calls dispatch.
The only reasons this is bugging me is Z's credibility and Serino's credibility. I don't see a first encounter as affecting the ultimate outcome at all.
Well, it still sounds like pure speculation by Serino (if in fact Serino said this.) Honestly, what bothers me more if indeed Serino is speculating this, is that it seems to me that if Martin initiated a confrontation first, Zimmerman’s account of self-defense following an assault by Martin is more credible to me, not less. But his judgment in leaving his car to find Martin is more difficult to explain, given his history of reluctance to personally confront suspicious people in the neighborhood.