Jake - And I think you missed the point of my reply. We're not hypothesizing here, we're talking about an actual incident. The reason I twisted it round a bit was to point out that the reason a SWAT team or equivalent plans to the enth degree and 'wears all the gear' as you put it, is because they are planning for worst case scenario. Why are they planning for worst case scenario? Because the people they are going to apprehend usually give them reason to do so. And yes, you are right, sometimes despite all the planning, things go wrong and team members get shot, although you are concentrating on that point, where in reality most situations are resolved with no shots fired by either party, let alone a team member being injured or killed.
But what I'm saying in this exact case here is that the homeowners were not doing all the things you advocate. Of course it's possible if they were, as I've already said, the outcome could have been different, for better or for worse. However, they weren't, and most likely had never considered the concept, and even if they had a gun, it would most likely, in this exact case, have not helped. As someone else pointed out above (which mirrors my thoughts on this), my feeling is that it is likely that one of the perps, either by accident or design, identified himself to the homeowners, which was the primary reason for their deaths.