You might google site:news.ycombinator.com , because you guys aren't the first nor the last to have this problem.
It really does seem to be a rather mysterious process if you're this far out of the norm though. I'm sure every additional datapoint will help.
This hypothesis has the advantage of explaining the system's byzantine complexity, which often seems irrational: it's a membrane. The upper tier of candidates (those with lawyers) are able to penetrate the membrane more readily than the lower tier.