Your happenstance is indicative of the way the world is degenerating in the most alarming of fashions. A simple act of closing your door sets someone in a bipolar rage. You did a good job of keeping your cool, diffusing the situation, and most of all, keeping your child safe. Remember the gun is not the first thing to turn to but should only be used if there is no other alternative.
Your example is yet another reason to never leave the safety of your fortress without your EDC gun AND your BUG. I gave ankle holsters a try for awhile but found them to be uncomfortable and not the easiest to get at.
My EDC is a Kimber Pro Carry in a Galco OWB belt holster worn at the 2:30 position. I wear longer outside shirts to cover my artillery. My BUG is a Kimber Ultra Carry in a Rhino Holster worn at the 10:30 position. I like this setup as it gives me good access while I am driving to get at a gun as the BUG is in a cross draw position.
I carry a double mag pouch with 8 round magazines which will fit into either gun. It does stick out of the Ultra Carry but if it ever got to the point that I would need to use that gun with an 8 round mag, I don't think I would be gigged any points for appearance.
As I have said before in this Forum, the way one carries is a matter of personal preference and you may have to experiment somewhat as most of us have done. The end result is you will determine what works best for you and in all likelihood, have a box of useless holsters that could fall into the category of "what was I thinking."
And of course, if you are going to carry, carry all time. As you have seen, all it takes is once to be without a gun and that will be the time you will most need it. It is far better to have it and never have to use it then to need it and not have it.
May the Schwartz Be With You.
NRA Life Member