Bettini, E3, explanation?
 

Any word how/why his RD snapped? Any close-up pics? I couldn't find one.

I have seen the video, he appeared be pedaling normally up a slight gradient when his chain went slack due to the break. He then sees the problem and throws his bike down in disgust. No close ups seen yet...

Inferior campy technology?;) I have seen a few pictures of the carbon fiber cages snapping on campy derailleurs.

I heard a rumor that the RD broke because the dropout broke...

I had an Ultegra 6600 RD explode into pieces because the chain broke and got stuck in the derailleur while I was climbing... Might be a broken chain.

limit screw out by a few mm....$350 derailleur meets spokes.

Yes, plus chain slapping around on evil bumpy road with possessed Bettini cranking hard...my perfectly adjusted derailleur can be pushed towards the spokes with surprisingly little pressure from my finger.

kassein destroy bikes.

especially those self-combustible CF bikes.