Nobody looks at it that way, except you in setting up your own straw man so you can knock it down.
Wrong. That was the narrative established early on, and the fact that you think it has been fully overturned in every mind even now, is a strong indication you've never visited the forums at JusticeQuest, or Huffington Post, or watched Dr. Phil's audience when the Ostermans came on... or talked to random people who don't follow this case closely. PLENTY of people still have the lil' 12 year old boy in their head. Trust me.
What is relevant, and that you never address is, Zimmerman thought Martin was someone he wasn't, doing something he wasn't doing.
He thought he looked suspicious enough to merit the police taking a look. I've had the police called to check me out when I was younger and doing absolutely nothing wrong, it's fine... you just explain what you're up to to the cop, and that's that. If a neighbor approaches you to ask what you're doing, it might be some old busy body with nothing better than to stare out the window all night... okay, so just politely explain. No biggy. You can make fun of them after they walk away. Unless you need to be Mr. Badass and have a girl to impress, maybe.
As for thinking Trayvon was someone he wasn't? He thought Trayvon was likely a burglar. The stolen jewelry and bent screwdriver the school security found in Trayvon's back pack prove that he was. So... yea.
He took action based on those mistakes. He expressed opinions based on those mistakes. Okay... but the actions were legal, the opinions were legal to have and express, and the "mistakes" haven't been clearly demonstrated to be mistakes. Do you know for a rock solid fact that Trayvon wasn't casing places to return to to burglarize later that night? Do you? Answer honestly.
Whether or not he's guilty of the crimes he's charged with, there's really no question he made big mistakes. I question that. With perfect hindsight, staying in the car certainly was the better move. At the time, he just thought he was going to get a better vantage point to see this person exiting the community at a great distance from him, so he could pass that info on to police when they arrived or called him back. This is after dispatch said twice "keep an eye on him" "let us know if he does anything else" he agreed to stop "following" and I think what he took that to mean was stop proceeding in the direction this kid went. He did stop that, as far as we can tell. That doesn't mean he has to scurry immediately back to his truck, it's his fucking neighborhood. He's the watch, he lives there, Trayvon is a guest of a guest, who's there while married to his second wife, at least, to hook up with a third, at least, mistress.
And its entirely reasonable to come to a conclusion that the killing was another mistake, which needs to be determined in a reasoned, judicious manner.
Even if every thing GZ did or thought leading up to that moment when Trayvon was on top of him beating him was done while laboring under a host of misapprehensions about who Trayvon was and what he was up to, at that point none of that matters anymore... maybe Trayvon wasn't intending to burglarize that night, maybe maybe maybe, but he was enough of a thug and criminal at that moment to be feloniously assaulting Zimmerman, which justifies the firing of the weapon into his chest regardless of any other consideration.
If I keep an eye on someone walking into my backyard and go out there to ask what they're doing, but what I didn't realize is that my wife had contracted some gardeners and he's one of them coming to see how big of a job it's going to be, I was wrong about who he was... sure, but does that mean if he freaks out when I come to ask him the question, he can do anything and everything he wishes up to and including beating my ass to death... because I was wrong?
And did GZ know he was wrong at the time of the shoot? If he even was wrong...? Trayvon had the opportunity to explain himself and let GZ know he was, supposedly, wrong about him... he was more interested in throwing punches than coming to understandings.