Better question: Also, why didn't you physically get in your car, and call the cops then? You said you were about to. Drawing was always taught to me as the last possible route before death, and I would have handed him everything except the gun that is my lifeline, while attempting to gather as many details as possible. He leaves with his swag, I leave with my life. Go back in the gas station call 911 with the description of my car, name, license, car contents, etc. I think we needed the expanded version.
Seriously though, Glad you are ok. Just trying to gain insight.
IMO, questions would that be asked if the incident would gone way south.