Yes. Counterfeits of the Kafka rollerball circulated first; from 2005 fake fountain pens and ballpoints from the 2004 Writers Edition Franz Kafka joined them, so that the series was being offered in imitation as a complete set.
The clearest pointer lies in the nib: if it is stamped “Iridium Point”, it is an off-the-shelf bought-in nib of a kind Montblanc has never used. Equally telling are papers supplied with a pen that do not belong to the model, a Bohème guarantee booklet with a Kafka pen for instance. Genuine editions are delivered with documents specific to the model; conversely, the papers supplied prove nothing in themselves, because cases, booklets and certificates are traded separately and bought in expressly to dress up fakes.
Anyone buying a Writers Edition second-hand should therefore always consider nib, engravings, cap ring lettering and documents together, and in case of doubt take the price as a warning: with limited editions, offers well below the usual collector level are almost never a bargain.