I used to run a brake and muffler shop, and personnaly did about 30 or 40 oil changes a week for six years since I was the weakest mechanic and oil changes are the easiest task. In that time I think I started an engine with no oil in it twice. Both times the warning light caught my eye and I shut the car down within a couple seconds.
So either:
A) Non-idiots can occasionally make a mistake too
or
B)See A.
So either:
A) Non-idiots can occasionally make a mistake too
or
B)See A.