Trayvon was up to no good and went after Zimmerman because he felt “dissed” that Zimmerman was watching him—as told to by the police dispatcher. I think there was also an uninvolved witness to the fact that Zimmerman was being violently attacked by Trayvon.
What you said are all true in the case of Trayvon Martin. Zimmerman was in danger and had to defend himself as Trayvon ATTACKED HIM and was pummeling him to the ground MMA style as a witness said.
What’s the excuse of the guys who were following Arbery in their vehicle?