I guess it depends on who was doing the complaining. Was he in charge? If not, no big deal-especially if he didn't see a gun. My license sits behind my driver's license where I can pull it out or not, as needed.
I suggest you find one of the upper belts who may be interested in some extended training and work on retention techniques and disarms. I used to do this with another master. After the kids class was over we'd lock the doors, pull the shades, and work on the firearms stuff, integrating it into our empty hand techniques. Check with your instructor to make sure it's OK. He may have some good ideas of his own to share. If he's absolutely against it, You are on your own. My instructor wasn't into carrying firearms, but had no problem with his instructors training with them. We had LEOs and military types as well as armed security and private citizens training there so a number of us saw the need for integrated training. I prefer to work with a real weapon rather than a plastic one. The weight of it changes the techniques as it has more inertia. One caveat though, make sure you both clear the weapon, and only work two people at a time. That way you don't have a room full of guns getting tossed around and sweeping each other.