I had the same thing happen with a Brisbane m/c tyre specialist on my ST1100 rear.
I'd only had it a few months, and as I rode away from the place I heard a little "clunk" but thought nothing of it.
Rode it for weeks, including some quite inspiring speeds. Put it in to a Honda shop for a service and they told me the rear axle nut was only finger tight. I faxed a letter to the offenders and they rang inviting me to go there again and they'd "look after me". "Nah," I said, "You only get one chance at looking after me." It sounded to me like an offer the Mafia would make. "Here's and offer ya cain't refuse!"