I have been in the business of speaking to people who have been involved in critical incidents for well over twenty years. It has been my experience, not supposition, that many of those people tailor the story to make themselves look better. So no, it doesn’t bother me.
What I look at is not simply Zimmerman’s words, but the evidence in this case. The evidence; Zimmerman’s clothes being wet on the back, Zimmerman’s injuries consistent with having his head slammed into the ground, along with a broken nose, along with witness’ accounts that someone yelling for help and that being one of the first things Zimmerman says after shooting someone. Zimmerman has to be a calculating person to be able to come up with that at that very second.
Monday morning quarterbacks may not see details such as that as important, but things like that said contemporaneous with the incident are very important.
I am not trying to be disrespectful, but I think your idea of SYG is wrong. Stand your ground means that you may defend yourself and not retreat if you are being attacked. I cannot find any evidence so far that indicates Zimmerman attacked Martin, but if you know of some please let me know I’d be willing to listen. Stand your ground does not allow you to assault someone that is doing something which is legal but creepy to you.