Yes, I'm surprised too, as its only lasted just over 6k miles on a well looked after bike with no pitting/damage on leg so it must just be a one-off seal issue. Luckily it's only the near side so no issues with front brake to deal with. In all other respects the bike's been trouble free apart from having to fit new indicator relay which required removal of most of the fairing panels which looks dramatic but is actually quite a straight forward job.
Having followed forum advice (Cortez etc), the handling has been 100% transformed with Michelin Power Pures, along much better screen (Bondi) and Givi rack and V46 top box (matching white cover) bought online from Italy as its far cheaper than the UK.