Can you give another example of this kind of mistake? I mean something on the order of magnitude of signing off on direct ownership of 9,000,000 shares of stock? After all, that is sort of like signing the registration application for your cousin's Maseratti, isn't it? You're going to know you don't own that vehicle and that the registration will be wrongly in your name, even if you are business partners with the guy. Plus he isn't going to be too happy about it when he finds out, assuming he hasn't actually asked you to do it for some reason.
I don't think I know a single individual, smart or not so smart, who would make that kind of mistake.