If it's working now, I would not worry about it. If you have a problem again in the future, it is most likely a voltage (low or high) issue. I have had this problem happen in several campers. Microwave touch screens are incredibly sensitive to voltage and I've always assumed to static electricity as well. This can be an early warning of an inverter or wiring problem, but I wouldn't worry about it if you have no other problems and it's only happened once. I have always assumed it was a problem with moving vehicles using appliances basically designed for a house (meaning no grounding rod to ground, etc.). I'm no electrician and not trying to be, though, so I could be way off. As far as modern kitchen appliances go these days though, I would say if anything works today then you are lucky.