Bah. It cannot be stressed enough - you did nothing wrong. If you were courteous at all, you weren’t a bad customer. If you actually apologized and treated the employees like humans? You were a good customer.
I’ve had an experience being a bad employee. I was working concession at a movie theater this summer. I was on one of the auxilliary stands, so I was the only one working, and the popcorn butter isn’t self-serve down there; we do it behind the counter. A woman ordered a large popcorn, and asked me to slather it in butter, which I did. A little bit dripped onto the side of the bag, and as I was putting it down on the counter, it tipped over, and dumped out onto her blouse.
I was absolutely mortified and for a horrible instant, was certain she’d be furious, rage at me, then go and bitch at my manager.
Instead, she laughed it off incredibly graciously, and told me a story about the time she was working as a caterer and accidently dropped a hot-fudge sundae on a customer’s lap at a formal function, thereby ruining his several-hundred-dollar suit. She also tipped me, which just blew me away - that is a good customer.