What could you POSSIBLY have done to upset a guest?
Listen, its going to happen. The best thing to do is get over it.... NOW. If you keep worrying about it, you're gonna be miserable. I've had about 2-3 complaints a year. For ringing them up too fast when the lines were long, for not asking if they found everything (we read a paper saying NOT to), for not magically pulling out the RED FURBY that a guest wanted because online it said we had it (yes, we had a furby but an assortment of colors), to flicking off a guest for almost running me over in the parking lot. YOU ARE NOT IN TROUBLE. you might have had a very slight, not even really a coaching, coaching. But until you sign a paper and you're put on corrective action, you have nothing to be worried about.