Sounds like the same thing that happened to you happened to my buddy with his R1200RT a few years ago- he "spun" a driveshaft. The elastomer bond between the inner & outer shaft tubes failed. He was on his way to S.D. from JAX , attempting a 50CC. It happened near Tallahassee. The bike was still under warranty, but the local BMW dealer wanted $1,500 up-front to look at the bike since they thought the clutch may have failed due to abuse.
My buddy rented a diesel pick-up and hauled the bike ( and his butt ) up to Green Bay to his dealer there.
BMW made him whole on his claim for the room & truck rental, BTW.
Unfortunately, it took his dealer a month to get the replacement drive shaft.
I checked, the driveshaft for the K1600 is the same design as for the R1200RT.