Once Trayvon was dead, there was no other possible threat to Zimmerman and he did the right thing by staying.
This gal, didn’t know if there were or were going to be threats to here in the immediate future. For that reason, she was wise to leave the A.O.
Zimmerman thought Martin was still alive. I don’t think he found out Martin was dead until he after he arrived at the police station later that evening.
Even after shooting Martin, Zimmerman flipped him over and was straddling his back, holding down his arms and asking people now on scene to help him keep Martin subdued.