"We've been attacked. We won. We are the exemptions to the rule."
Sorry to hear you had to go through that. A good friend of mine and his family got burgled, beaten and raped during a long and horrible night a few years ago in Joburg. Luckily they all survived. Fences, watchmen, alarms, grills, locks etc were of no help. No dogs, no guns.
Up here, the average criminals are a little less organised and the crime level is nowhere near as high. I have no statistics to show it, but I have hardly ever heard of a break-in here where there wasn't at least one inside man. A shotgun, rifles and/or handguns in a house are more an incentive to try a break-in than a deterrent. As others said, a good dog goes a long way, but its far from a guarantee. After some unmentionables poisoned our little Buddy late last year, we got another one and he's doing alright, so far. We also try to take good care of our house staff (they have been with us for many years) and make sure we stay friendly and close with the neighbors.
Back on topic: I do believe there may be something to the racking theory under some circumstances against some criminals, but I certainly wouldn't rely on it.