Disturbing news Maddog, and of course relieved that you were not injured.Why do you figure the rear end slipped out? Something on the road? Abrupt throttle? Car tire on the rear?
Have you determined what may have contributed to the slip?
That is the thing that bothers me the most about this incident. After moving the bike to the shoulder, I walked the transition road looking for what might have caused the tire to slip but I couldn't find anything. Now, granted it was 6:00 AM and the sun wasn't up, so the lighting wasn't too good but I couldn't see anything that might have caused it. No oil, no antifreeze, no pieces of tire, nothing. And I checked the tire on the bike and couldn't find any evidence of fluids.
And it definitely wasn't abrupt throttle; I've hit slippery stuff on this same road before. That's why I took it at a nice easy pace with smooth throttle inputs.
Now I'm sure some guys get pretty good milage out of a car tire on the back, but I'm a traditionalist and stick with proven performers, like a Michelin Pilot Road. : )