Engine Failure

NOT the T-Dub

Riding southbound on I-5 yesterday on my way to South Sound BMWs WABDR Planning event, hauling 60mph at 8200 RPM, the mighty T-Dub just quit. No loud noises, no smoke, it just died and I rolled to a stop on the shoulder.
First thought was a main fuse, or loss of fuel.  I walked the bike a few hundred yards to the end of the guard rail and rolled her onto the grass.
Soon Paul Bullard stopped on his ST1300.  He'd spotted the T-Dub from the fast lane and did a loop around.
After a little diagnosis, pulling the plug, verifying spark and a normal plug color, the exhaust valve was visible through the spark plug hole, hanging down in the cylinder. It wasn't moving when the engine was turned over by the starter. There was a sucking and poofing at the tail pipe when the start was cranked, so I don't know what this means, whether the intake valve is working or not.  The exhaust valve was hanging way further into the cylinder than normal, so it may be possible the cam chain is still turning the valve cams and intake valve, and I have a issue only on the exhaust side.
So Paul went on his way and my lovely wife came down in the van and hauled my broken beauty home.
Thanks Paul, for stopping and helping in the diagnosis.  And thanks to Dana for coming to the rescue.
This morning I'm tearing into it and I will share.