Applying for a position is a much lower bar than having any chance of landing the position.

I’ve interviewed someone for a programming position. The guy practically nailed the standard quiz (done at leisure before the interview), but was unable to explain why he answered what he answered. When we got to reviewing a little program (compare two strings, see if the distribution of letters is the same), he could not walk me through it. He was applying for a programming position, and could not explain his "own" impressively correct programming answers.

Well at least postdocs have a PhD, that they had to defend in front of a chalk board I presume. Still, sometimes, frauds do slip through.