Because your gaskets over the plug wells were leaking...and when you pulled the plugs, oil got on the threads. Anyway, hope that's why. When I did my vcg, I had a coating of oil in the bottom of 6 and just a tad in 5. Not sure you looked, but wouldn't surprise me if I'm right and that's all it was. Hope so.
I'm so depressed. No one wants to come see me. :(
Mangofy your E46!