You could spend a lot of time trying to find out such things as whether or not the county operated long term care facility would have the same type of hiring requirements as the commission on aging and you'd still not have answered anything meaningful in your situation. City, state and federal are the big three that are sometimes governed by civil service requirements different from most jobs, certainly from most private industry jobs because they are usually governed by civil service. If you deal with popularly elected officials, without civil service, there'd be a danger they'd clean house each time a new administration came in and that they'd sell jobs to buy votes. But there is also to be remembered that any federal contractor may be under requirement to interview the qualified veteran in many cases, veterans preference is huge in their requirement for who they do and do not have to interview, if not hire.
A "council on aging" may be a privately operated entity which administers federal aging money, that's usually the case. Either way, whether they are both the same type of government employer, which I suspect not, based on my years of experience with such, there's nothing illegal about what they are telling you. They pegged you as someone who'd be unpleasant to interview again. Before even bothering to present as borderline polite, you walked out. You felt they were wasting your time. They may have felt the same. Why should they be forced to interview you again at this point? What your wife is calling blacklisting and saying is illegal is not, but if you feel so led, you might want to let yourself be told this by a labor attorney in your area.
