The thing to understand here is that
Stand Your Ground laws do not exist in some segregated section of Florida's criminal code. They are not bracketed off from the rest of Florida's "standard" self-defense laws.
Stand Your Ground laws are integral to the very meaning of self-defense in the state.
I do not think you can argue that Zimmerman would have been convicted if not for Stand Your Ground. But you certainly can't argue that the law had "nothing" to do with this case. And you most certainly can argue that SYG reduced the chances of Zimmerman being arrested. If that arrest had happened we probably would not be talking about this case right now.
More: Via Andrew, here is a juror directly (if mistakenly) citing Stand Your Ground as part of why they acquitted:
COOPER: Because of the two options you had, second degree murder or manslaughter, you felt neither applied?
JUROR: Right. Because of the heat of the moment and the Stand Your Ground. He had a right to defend himself. If he felt threatened that his life was going to be taken away from him or he was going to have bodily harm, he had a right
Again,
it is simply not supportable to say that Stand Your Ground had "nothing" to do with this case.