cotb,
just coincidence, no secret, happens a lot.
pulling pitch to slow the main rotor, especially at low rpm can and does damage the straps in the head. ask an engineer. (didn't know there where straps in the head???) i think that's what john is referring to.
that is why you should never raise the collective and at the same time move the cyclic through full travel when the blades are static.
it can be very expensive.