A couple weeks ago, while walking through a display towards the store counter, I inadvertantly knocked over a display of glass bottles thrust out into the middle of the isle. I'm just glad it wasn't expensive! The clerk noticed my firearm immediately, and said, "Don't worry about it," but I thought this would be an excellent opportunity to demonstrate the fact that we're upright citizens, and insisted on paying for it.
He was rather surprised, and I had to say, "No, no - I knocked it over, I'll pay for it" several times. I even offered to mop it up, but he laughed and said he couldn't possibly let me go that far!