I do have a mechanical background, funny enough was a motor technician for BMW on the car side for several years. I was convinced mine was oil as the consistency of the substance from the right and left fork for was different. It doesn't need to be flooding down the for fork for it to be oil, all it takes is a bit of grit to bypass the dust seal and disrupt the mating of the seal and for leg. I've checked the bike over since its return and I no longer get a trace of oily substance when bouncing the forks. I was informed the dust seals were removed and all excess grease cleaned out. I do have a little tool called a seal mate that you can use to dislodge any contaminants from a fork seal and its definitely worked for me in the past. If the dealer has used something like this who knows or if it was grease I'm not convinced. I will take her for a spin later and see how I get on.