If this was after the first service, my guess is it is from the oil filter cover.
Either the o-rings for the cover got ruined when the first service was done (AFAIK these o-rings are still not available) or the cover itself got ruined in the first service. When I bought an oil filter to do an oil change a couple of weeks ago, the dealer mentioned to me that if care wasn't taken when removing the oil filter cover it was easy to break a mounting flange off the cover. If the dealer partially damaged a flange doing the first service oil change it could have fatigued with vibration causing an increasingly larger oil leak.