vespasianus

Well, this is worrisome. And mrblue, you should have played the lottery!

gfk_velo

Were these derailleurs subject to warranty claims?
It could be that the spring's "hook" was not within spec, so if it came out once, potentially it could do it again.

Obviously, from Campagnolo's point of view, we would hope that the items were subject to warranty claim (odd though that might sound).
Part of the reason there is a warranty process, apart from correcting the problem for the user, it enables the factory to determine whether an issue is a production problem and to fix it, or something else ... even in non-warranty cases, there are lessons to be learned. Things are done on the way to, or in, the market, that don't happen in testing in the lab, with the teams or with other evaluation riders - you think you have covered everything, then suddenly a curve-ball gets thrown ...

Which brings us to the "clicky pivot" ...

This was an oddity. In RDs not subject to impact, it was caused by heat - not in production, nor when in the hands of the user - but eventually the cause was isolated to items getting extremely hot during transport.
It appears that derailleurs near the top of the transport load, right under the roof of the truck, were getting far hotter from direct sunlight effects than anyone had ever thought would cause an issue. Once the problem was traced, the affected parts were modified.