I really have no idea about that. The thing I have been paying attention to is who claims whose voice is the one screaming out. Trayvon's dad (stepdad?) initially said that the scream was not from Trayvon and no one is making any big deal about it.
In my opinion GZ has a soft spoken voice. When the one witness said she thought it was TM because it sounded like a younger soft voice I can’t say for sure it would be TM. Did you hear how deep the 15 year old kids voice was? Although we have not heard TM’s voice.