I don't think the call is edited at all. So, if BOTH Serino's story of two speaking encounters, and the call are to be squared, they can't be in the same timeframe. I see two possibilities IF there was a first conversation, and both of them have the first conversation happening before the recorded call.
1. Z watching TM, TM comes over and they talk, window rolled up. Z keeps watching, and calls dispatch. Z's account over the phone is honest - TM stares, approaches, stares more, hands in waistband, runs.
2. Z watching TM, TM comes over and they talk, window rolled up. TM runs away. Z pissed. Z calls dispatch and makes up the narrative.
I don't see time for the recorded call, THEN two separate spoken encounters, the first with Z back in his truck. The evidence diverges too far from that theory.
1. Z watching TM, TM comes over and they talk, window rolled up. Z keeps watching, and calls dispatch. Z's account over the phone is honest - TM stares, approaches, stares more, hands in waistband, runs.
2. Z watching TM, TM comes over and they talk, window rolled up. TM runs away. Z pissed. Z calls dispatch and makes up the narrative.
I don't see time for the recorded call, THEN two separate spoken encounters, the first with Z back in his truck. The evidence diverges too far from that theory.
I don't believe your scenario of a confrontation before the dispatch call works. If Zimmerman had a confrontation with Martin before he called SFD, then wouldn't he have known that Martin was black? Instead, when the dispatcher asks "is he white, black, hispanic" Zimmerman answers "he looks black". Then later, when Martin gets closer to him, he confirms by saying "he's black".