I'd urge you to consider the legal and common sense ramifications of this case by expanding outside these specific set of facts. Should anyone with a role in public safety be subject to a mental/pysch eval at the drop of a hat? Driving puts "human lives in the balance" and is more dangerous than flying, so are all drivers included? Do the benefits here really outweigh the costs? What happens in a disaster, are all persons immediately sent home to await mental/pysch evals before they can begin their duties? It sounds crazy but that's what is being advocated.
Put your example in context of the complaint: sales person missed one call and seemed distracted but able to discuss the sales points with others in immediate preparation for the meeting. Happens all the time. People get nervous or have other items on their mind.
ADM and CRM are more important than ever. Crews need to work together and monitor each other to prevent minor incidents from becoming major accidents, including honest self assessments.