Pretty consistent responses that fit into a few basic camps:
1) Limit risk exposure by avoiding social contact. (Don't go to the bar.)
and/or
2) Limit risk exposure by avoiding excessive immediate trust. (Don't take people home with you.)
or
3. Respond to the situations as, and after, they come up. (Shoot them/have your wife shoot them/whatever.)
I'm not sure about any of those answers as I'll explain in a bit. But, first....
But you are in Texas, Ed, and the incident happened
in Texas.
Good point. The incident which inspired this thread happened in TX but there is no rule saying the next incident will. It happened to involve LEOs but, again, may not next time.
I'll give you an example of how it may go down next time:
You go to church. After services you talk to one of the clergy and invite him/her over for dinner with your family. (S)he asks if it's OK to bring along two teenagers who have been very active in volunteering for the church/are great kids/whatever. (S)he calls them over and introduces you and they seem to be good kids. Everyone has a fantastic dinner and the kids are super polite. After a while the clergy person you invited over says (s)he must leave and the two teens ask, "Can we finish our game of foosball? We can walk home after." You think, "gee, what good kids those are!" and say yes.
In both cases the key events were:
1) You went to a place of social gathering (church/bar)
2) You encountered a trusted individual (clergy/LEO friend)
3) Trusted individual introduced you to two others (volunteers/other LEOs), describing them as trustworthy.
4) You allow/encourage the group to enter your home for social/recreational purposes
5) The individual best known to you (clergy/LEO friend) leaves and you allow the new acquaintances to stay.
At that point, the choice of outcomes is largely in the guest's hands. If they really were trustworthy they'll go home and you may end up with new friends and deeper ties to the community. If they were somewhat trustworthy they may go home as friends but start telling people "the guy at <your address> has a really nice house full of great stuff!" increasing your chances of being burglarized. If they are somewhat untrustworthy you may find you've "misplaced" something or the pharmacy shorted you one or two pills but never really track down an exact cause. If they are very untrustworthy they may use your blood in their heathen rituals.
Or, more accurately, they control whether they will TRY to do those things. If you've got a "clean" part of your house for entertaining guests without exposing them to anything too interesting or desirable you can limit the "somewhat" outcomes (nothing to talk about/nothing to steal) without preventing the very positive or very negative. If you carry discrete protection while hosting you can at least respond to the very negative without preventing the very positive. Being the host gives you a lot of control but the choice to initiate is still theirs.
That's why I'm not entirely sure about the first two solutions (avoid social contact/avoid trust). I think the costs are high and the risks can usually be minimized in other ways. Bringing people to your place actually gives you some advantages from a security standpoint. Your home is generally a LOT safer than a park, wandering the streets, or going to someone else's house.
Which brings up the question, Was the guy who inspired this thread thinking security? I suspect he was. Not only the choice of friends, but he appears to have been using a classic "clean" environment for hosting. Garage game rooms are easy clean hosting evironments because you should do most of the work anyway. If your garage opens directly onto a public street you should be able to quickly hide/secure anything too desirable to prevent drive-by casing and smash-n-grabs. Once you've done that it's easy to take the extra steps to make it really clean and use it as a "guy's less-trusted guest hosting environment". I suspect that's why the foosball table was there.
One of the things I've taken from this is the importance of video surveillance of hosting/clean areas of your home. If the victim in the story had a couple of video cameras in his garage he would be able to show exactly what happened. For all I know he did have video cameras and that's why the incident was taken as seriously as it was. Otherwise it would've been word against word.
Beyond that I'm not sure. In this case the guy lived. His attackers are being punished. He didn't lose anything except some innocence... so the response was fitting. In other scenarios he could have lost a lot more and a more forceful response would've been called for in my book.