I just reread your post 1k and zeroed in on the part about your dog. My first dog was named Falco, not a common name. You wouldn't have named your dog after a particular Austrian artist from the 80's, would you?
Back to the real story. It's an uneasy feeling to have something like that happen, but think how much worse you would feel if you hadn't almost shot the dude because you didn't have a gun on you-- better his close call than yours...
The most important thing now is that you have emphasized to your boss that you own a gun for personal protection and you need fare warning if folks are stopping by, nothing wrong with that. As long as you have the drop on the person, you should be able to watch them for a minute to determine whether they are friend (don't shoot), foe (shoot), or naive jackass (pistol whip).
I once walked out to our barn expecting to have to shoot a thief after being warned by my two lovable mutts, but instead I ended up pointing a pistol at my future father-in-law. To this day he claims that the only reason he calls me before coming over now is because he would hate to have to take my pistol from me if I ever pointed it at him again, but regardless of the truth, the point is that he calls before he comes over