While I agree with most of your comments, the sad fact is that it does happen more often than we hear about. The FAA does not advertise it since it does not reflect well on the FAA when a DPE goes rogue. The reason for going rogue? It’s all about the MONEY until they get caught. DPEs are selected based on specific criteria they have to meet. They are then trained/indoctrinated on how to conduct checkrides and how to conduct themselves when performing tasks on behalf of the FAA. They also receive recurrent training as a DPE.
When they go off the reservation, it’s purely intentional and it’s always for the MONEY. I don’t feel sorry for the applicants either. The Airman Certification Standards are very clear about what’s required so if the applicant see’s things are not unfolding as they should during a check, the applicant should terminate the test. A simple, “I feel like I’m about to throw up,” will end the check immediately without tipping off the rogue DPE. Typically, the applicant never reports the DPE, it’s usually a third party who finds out what is going on and reports it. In fact, most applicants spread the word to other potential applicants to use the rogue DPE because he/she gives an “easy checkride.” Both rogue DPE and applicants who partake are equally guilty and cannot plead ignorance as a valid reason for their actions. Those 140 applicants being recalled thought they got away with something. Now they’re whining because they got caught. There are consequences for bad behavior. Not all of the 140 will retake a check because some of them know they cannot pass a check. Many others will fail a subsequent check as well. A few may pass a real check too. They are not innocent victims.