> How does it not appear to be broken, when they approved the guy as a Director even though he had nearly zero experience as a manager?

There are diminishing marginal returns on better screening. Most people are pretty honest, and of those people who aren't honest, most of those people will mess up their deception; this means that a pretty basic level of screening brings a lot of value while only letting through a few bad apples.

One could intensify the screening to avoid more bad apples, but that costs money and increases the false positive rate. At some point, it's better to just hire people and fire them when it doesn't work out.