It could be that, though it seems weird it would have happened while cruising down the highway, esp. the way it works. I will be curious to see what others post - hopefully not the stator, as it sounds like that can be a bit of a bugger.
Good luck : )
7800 orig mi when purchased Jan 2011
Turned 11,000 mi Nov 2011
Taillight relocation kit
Chad's highway peg mounts
Otherwise, all stock
"But it's a dry heat - like the inside of an oven"