Self defense is subjective.. This case was more of a matter of opinion, than an application of Law for the Jury..
I would not agree with you, it was a pretty clear-cut case.
Cops, prosecutors and juries look at a couple of things:
Who was the aggressor?
Who instigated a violent act?
Following someone and questioning them does not fall under either of these. Throwing the first punch does, the juror believes TM hit first, he was also seen on top of GZ throwing punches.