I agree with being able to explain your acts or concerns but in general, I as a non-sworn armed citizen or licensed security officer would not give first aid to a wounded subject unless there were other officers on scene to help me or a bystander with a medical background offered to help.
I'd add that in 75-80% of these critical incidents no one would jump up and provide help. Most bystanders or crowds would wait for fire-rescue/EMS.
About a year & a half ago, I saw a young male(TV) get cut with a small knife after a dispute with another young male in a 7-11 store parking lot.
I was working a security post at a low end hotel across the street. The victim had a small gash in his chest & a lot of blood. I contacted 911/fire-rescue & law enforcement. The subject was arrested(with a police K9 unit) & charged for the crime but was later released & the entire case closed.
To provide aid or medical care in a emergency is good but don't put your safety at risk.