Would you? If you've heard that a lot, you probably won't. There's nothing wrong per se - the person could be right, but it's more likely that he is wrong[1]. But something could be said about this person's approach to finding a co-founder, i.e. if he's going about his co-founder search this way, he's probably doing other more serious mistakes other battle-hardened entrepreneurs have learned the hard way.

It's a mental decision-making shortcut. Don't get hung up over little things such as the OP's actual words, like the way the interviewee answers a questions, fidgets, etc. It's just a mental shortcut signal. Sure the OP could be wrong. But he could also be right. How do you know you're not wrong? VCs take a million meetings, make a million decisions, they have LOTS of data to test how well they're doing. They are not random schmucks. Clearly they think about this day and night. Is it possible that they're all wrong and you're right?

Also - I'm not in VC so I can't comment from a position of being an insider, but consider this: if you were a stock trader with an uber stock trading algorithm, would you share it? No. I don't see why VCs would share their "algorithm" either. They're competing with the other VCs for deals in startups, and they each have their secret sauce. They also compete with each other for more investor money (from their LPs).

Lastly, consider this: would any anti-spam vendor fully disclose all their algorithms to detect spam? No, that would be dumb, because then spammers would know exactly how to circumvent them.

[1] Fact: most startups fail