I don't see what is controversial about this. Dude follows unarmed kid he thinks is causing mischief in the neighborhood, shoots him dead. Unarmed kid shot dead. Who gives a eff what happened in the interim?
This is where I am at. I mean, if they found a second gun, things would be diff, otherwise, it doesn't really matter to me. Zimm called 911 and was told to stop chasing. Zimm forced a confrontation, started losing confrontation, and decided to shoot.
In my mind, under this scenario, even if TM took the gun from Zimm and threatened him and Zimm then took it back and then shot TM, this would still be manslaughter imo because the confrontation was not only avoidable, but Zimm was told by the authorities to not create it.