I'm sorry. Neither one of you is qualified to have a gun because you are dealing with contingencies after they happen and not doing anywhere near the preparation needed. No one should have a gun unless they are fully trained AND that training can be employed automatically in a crisis. You both failed that test.
When I was a kid, we had a plan for when the fire alarm went off - everyone had a place to go (a meeting place outside the house), and NO ONE was to go back inside to get someone who wasn't there. No exceptions. No discussion of whether it was a false alarm or not. You train, and you implement the training every time. That's for a fire alarm. And you are dealing with a fire ARM!
Your husband is dealing with his hurt feelings (read: his ego) and you are dealing with whether your comments were appropriate. No one is really dealing with the fact that he pointed a gun at you. He could have pointed it at the children who might have run down the hall or slammed a door. You had enough time to say, "Whoa, point the gun down." You are so incredibly lucky that A) you had time to say it, B) he had time to say "Ooops" and C) he wasn't so out of it that he fired the gun. But if it had been a real intruder, he would have wasted valuable time, and the intruder would have overpowered him or fired first. So where's the benefit? And what if your kids had run down the hall and neglected to say, "Hey, Dad, it's me, your child, Sam. Please don't shoot me"???
My son used to do dog care for a neighbor. They had a special alarm code for "guests" in such situations, but they neglected to set it properly. So my son went in as scheduled to walk the dogs, punched in a code that didn't work which set off a silent alarm, and the alarm company got the signal and called the owners. The couple came home, no one called the police, and the homeowner decided to be a cowboy and grabbed a gun and started looking under beds and behind doors. My son, meanwhile, heard someone coming in, and was frightened. He hid in a closet. Any guesses about what happened next?
You and your husband want to have an intellectual discussion about who did the right thing, who was asleep, who was coherent enough to talk to the police (leaving the least coherent person in charge of a gun), and then get into a debate on whose feelings were hurt. I think you're missing the bigger issue.
There is no way, if I were a parent of your children's friends, that I would ever - EVER - allow my child in your home. It doesn't matter that you are probably very nice people who would feel terrible if my child were shot. It doesn't matter.