Glad to hear its all sorted. You're a brave man, but then I can totally understand your choice, as my bike is also my only transport, so I have to ride around problems or find a bus.
To be fair, this is the first time I've seen this issue on this forum, so it's probably a freak occurance and who knows, perhaps now the dealers had it happen they'll test ride the bikes after the first service... perhaps not.
At least people on here now know that it can happen and to make an extra check once their drive oils been changed. I stopped in traffic after about a mile on the ride back to the dealers and it was pretty obvious there was oil everywhere. So a very short ride after a service will show if its an issue.
She's back to normal now, and I've opened her up a bit now and am thoroughly enjoying the grunts, pops and other delights of the GS. onyack