I didn't realize I had cut in front of the same guy the second time until after I did it. The driver of the other vehicle did not have to hit his brakes either time.
How did you not see who you were cutting in front of, but know that the hole was big enough and manage to notice that he didn't hit his breaks? I'd think after the first confrontation you'd remember the guys car.
I would have slowed down and let him pass after the first time he got all up upset. Mouthing "sorry" usually goes a long way too.
And I do find it a little worrisome that being yelled at in traffic made you decide you need to be more heavily armed. You didn't need your .38, you wouldn't have needed a riot gun either. Careful driving and some conflict avoidance (talk to your wife about when waving is appropriate) would do much more to avoid repeats of the situation than a bigger gun would.
I've also thought a flashing "sorry" sign you could activate on the rear window would be a good idea for cars in general. I'd think a lot of conflict could be avoided that way.