I would say that a minor ding that is unrevealed by the applicant is automatically a major disqualifier, while there are some people with the same "ding" that are able to get in, because of a combination of forthrightness and agency need for their qualifications.

Having said that, I know of at least two people who are working in sensitive positions that shouldn't be there. They are, in my estimation, both unacceptable security risks, and I've done my level best to get them dismissed, but to no avail.

"Fairness" is not a consideration for hiring for Intelligence Agencies.