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".
I don't think it works either. That's why I'm puzzled, and wondering where Serino got that theory.
I also don't think a version works where there is Z's call, then Z back in his truck for a first encounter, then wait minutes, then go out for the second encounter. That theory has even more holes in it. Not enough time, for one, and nobody else is telling that version. Not Crump, not DeeDee, etc.