IMHO you did make a faux pas. My guess is that you already know that or it wouldn't still be on your mind. That said I am happy that your family is safe, but shooting in the air is not the best action to take in that situation. Having your weapon ready was warranted in the situation. Noone will ever know what the men on horses truely intended, but I think it was a very good thing that you were prepared to defend your family. Unfortunately bad people can be everywhere we go. I'm happy everything worked out in the end and no harm was done.