While I am glad your friends intend to 'arm' themselves....I hope they will not be under any illusion that the robbery "Wouldn't" have happened or that it won't happen again. The mere 'possession' of a firearm in no way wards off evil, it does however provide you a way (in some circumstances) to deal with it.The funny part about the whole conversation his wife shouts at him "you see if I had my CHL this wouldn't have happened".
In this situation....because the perps unwittingly showed their weapon (knife) at some distance, if either of the victims had been armed and displayed their weapon(s), it might well have caused the robbers to break off the encounter.(no guarantees of course).
I hope your friends realize that potentially...their very lives were at stake. I can get over feeling 'belittled', I can replace most monetary loss, but I can't restore LIFE (mine or my Wife's).
I know that most Men feel it is their duty to protect their Spouse (and it is), but this man's Wife needs to be able to protect Herself. There won't always be someone else (especially the Police) around to do it for you. Not to mention....having two armed individuals to combat a threat is generally better than one.
Then there is the NEED for practice and training. Having a firearm available gives you the 'means' to shoot, but you still need to know WHEN to shoot, when NOT to shoot and be good enough to hit your target.
I applaud you helping them get started. Good Job!