It's easy to pass judgement on a decision like that when so far removed from the context where/when it took place.

It's likely that answering yes to that question meant an instant rejection for the clearance AND summer job. The FBI was probably not inclined to spend money looking into such an obviously trivial matter just so some kid could get some work experience. "Sorry, try the McDonald's down the street."

That security officer did the author an incredibly big favor.