Robberies are unpredictable, chaotic events. I was robbed in a bad place, Villa 21. One of the assailants shoved a handgun to my abdomen. Everything happened so fast, I reacted, but not rationally. I resisted one of the thieves pulling on my fanny pack, so he punched me. I gave up the fanny pack. I then scurried to report the theft to the Prefectura. Within 40 minutes the Prefectura had nabbed two of the 3 bad guys, and recovered the nice camera I had described to them. In the little office they had the "handgun" which was actually a fake replica. I still think of what would have happened if one of the thieves actually had a real firearm and had discharged the firearm, forever rearraigning my intestinal tract. I was persistent in making the denuncia, appearing in court, and learning my 2 assailants each got 14 months in prison. The judge in the case made mention in a conversation that a person was robbed at night in Palermo, and got a fatal gunshot wound to the head.
My observations:
Foreigners are considered prime targets. They are presumed to be unable or unwilling to testify in criminal cases.
If bad people are running away from you, don't chase after them.
Your health is more valuable than the stuff on your person.
In the scant seconds of an encounter, you may not be able to manage your own reactions, let alone anticipate the actions of the thieves. Police receive training, are armed, and wear body armor, but still lose their lives in encounters.
Suerte.