Stuck - it manifests itself like retreating blade stall - ie a pitch nose up and a roll towards the retreating side of the disc. The recovery is the same - lower the lever and reduce the disc loading/G/aft cyclic.
It is most dangerous when in a hard turn to the right in an EC helo as it can roll you upside down. You have to be heavy/fast/aggressive with the controls to get into this situation so fly sensibly and sympathetically and you won't ever see it.
EC have been touting this 'phenomenon' as a safety device since they built the Gazelle - the servos are just not man enough for the job.