no, there hasnt.
there's been a COUPLE, and their always ones that look like they have been crashed in to the floor.
maybe they should come with a warranty slip stating "these brakes are designed to stop you from moving via friction between the pads and wheel, not the lever blade and floor."
i guess that would stop this misunderstanding in the future.
To keep on topic:
the brakes are good.
almost everyone that has them gets on well with them but a few people treat them badly and are surprised when they break as a result.
they are totally fine if you don't try and dig your own grave with them.