I had a friend, that his son couldn't get a job driving trucks cross country due to his driving record, to many tickets, but he got a job as a police man. We have a few state and locals police man who have hit cars from the rear and were found at fault but kept their job, as a truck driver, you would lose your job with most trucking firms that I know of.
If the department has lower standards they will have these kind of problems.
Who would hire a person with the kind of record as the officer listed in this story? They get hired everyday somewhere.