I don’t get what you mean. How will her lawsuit against the HOA go down in flames if it’s murder but not involuntary manslaughter (accident)?
Either way they’ll sue claiming the HOA had someone “unstable” person being watchman of the community. GZ wasn’t even on duty anyway.
He was a volunteer and not an employee. Therefore there is no respondeat superior liability unless Zimmerman was not only "on duty" but was acting within the course and scope of his duties as a volunteer. If he killed Martin through some personal motive (as the murder charge would suggest) then there would be no liability on the part of the HOA. They need to prove that this was an accident that occurred while the volunteer was working and that his actions were not criminal.