Enginair... you have a peculiar C210
Yes, I also learned during my training that the hobbs meter was linked to the oil pressure meter, about 3 years into it I was 'shown the light' by some seniors who thought the day dream had to end some day. Although it's possible that your master switch can be off and the hobbs still work on oil pressure activation, that is a more complex and expensive system... which isnt common here. I would not be surprised if somebody has pulled the foggles over your eyes and taught you something else, but I may stand corrected. As for 'DR' I know people in high places... who think the world of him, and say he is being unfairly punished for 'owning up' to something we've all done... tested our curiosities. What kind of fool would openly and honestly 'own up' to this though, does he not want to fight for an aviation future? - it sure is a battlefield out there!