Sadly, I had to take my bike back to Cotswold Motorrad after the 18,000 mile service last week. Fortunately, this only involves a minor detour from my commute.
After a couple of short trips, commuting 11 miles each way, I noticed a dark stain on the sump and a tell tale drop of oil on the base of the oil filter seal. I tried to tighten the filter by hand but it would not shift, so I dropped by the dealer on the way home from work today. Arrived at 520pm and left about 30 minutes later. They had the bike in the workshop pretty quickly, checked the torque which seemed correct at 12.5nM. So they have given the filter's seal an additional lube, a slight tweak to 13.5nM and cleaned the leaked oil off the sump.
Hopefully I will not have to return to the dealership.
The service today was good but I am rather disappointed I had to go looking for it.