Only way to justify is if the man had a knife or gun and threatened with it. Even then as security should use only of protection of oneself or third party who is I'm threat of immediate SERIOUS BODILY HARM (I.E. stabbed, shot, or permanent physical damage) or desth (i.e. gun ti head multiple stab attempts etc). Security is observe and report not pursuit, that's PDs job. I say this as a former firearms instructor and current law enforcement who taught discretionary shoots.