Fantasies of fighting off robbers, muggers, home intruders and protecting loved ones are easy to indulge in especially when a lot of effort (and probably money) has been invested in learning martial skills. The grim reality though, is that in every encounter there is a risk reward tradeoff to make. Are you willing to possibly bet your life on getting physical? At what point do you make the decision to hand over a wallet, get physical, run away etc. It's a very important question and one that many authors recommend you ask before you are in that situation.
It's ultimately a personal decision and should probably be a premeditated conscious decision, rather than reacting in the heat of the moment or letting an assailant make that decision for you.
This blog suggest walking away from a mugger after handing over your wallet and provides a news report of a good samaratian who got into trouble as well .
Meditations on Violence author Rory Miller is his book talks about thinking through many scenarios. His background is in the prison system and he talks widely about that. He suggests that should a loved one be taken hostage/ home invasion and you can get away you should do that - with the rationale that if they intend harm there is not much you can do to stop them but at least by escaping you can provide information to those that can help... tough one.
Well known martial arts author and counselling professional Ellis Amdur suggest verbal de-escalation as a tool. [NOTE: The scientific literature is unclear about the effectiveness of de-escalation in many situations]
more to come...