Ive been known to mark up a car or two. But I can safely say that I've never made any up that werent found and documented during disassembly.
Unfortunately, Ive seen cars that Ive built, several years down the road, that have been marked up like is being discussed. It bugs me. Not only do I know I didnt put them there, I also know that they werent on the car originally.
And maybe someone should tell these guys that the assembly line workers didnt dab/mark anything (except in rare instances)
dave