So, I have a very strong opinion of this whole matter, and the person behind it. I've forced myself to ignore everything I wanted to write or reply to about it, but what struck a chord was your perspective, which is that credentials should have been revoked.
Journalism is a set of very specialized jobs. It's also a small cultural subset and after a time, everyone knows everyone. When you change jobs in news, you either go to an another news organization or pretty much retire from news (meaning you leave it and go do something else - it's rare that you'd ever come back to it and the barrier to re-entry becomes steeper.) What I mean to say is that your reputation definitely precedes you and it sticks around for a very long time.
There are some in this thread who have written or implied that "most journalists" have no ethics or self-restraint and all they're guided by is the end result. In some organizations, that's true and those places keep their notoriety all to themselves. For every bad apple in every industry, there are thousands of notable ones who do their work, and more than enough of them have self-respect to uphold their integrity.
Having said all that, I don't disagree with what you're saying at all. But here's an anecdote to help illustrate the culture and level of trust typically found in news. In early 2013 Nelson Mandela got sick. Many news organizations prepared a number of packages for the eventuality of his death - that included everything ranging from special reports, photo galleries, videos, memorials, and other special projects. A very talented colleague of mine put together a montage of Nelson Mandela's 1994 acceptance speech being read by various children living in South Africa today. It was pretty moving and showed just how things changed in those 20 years since. The project was finished, and readied in case it was ever needed. Then in mid-2013, that person left us and went to work for a large national newspaper, which was a great career move for them.
Soon thereafter, a number of staff changes occurred and on the evening (local time) of Nelson Mandela's death, no one was left on duty who remembered the tribute package existed. The ones who did weren't on duty at the time and the material they could immediately put together was very lacking and would take some hours, perhaps a day to properly acknowledge the man and his work.
That ex-colleague of mine tried to get in touch with duty editors, but was unable to get through. Given the timing and possibility that this material would never see the light of day, they remotely logged into our CMS (because none of the credentials were yet revoked), prepared the material as a draft and sent a note to the entire office letting them know it was ready for publishing. Some of the recipients on that list probably didn't even yet know the sender had left the organization, but from the email trail were very grateful to have the package ready to go.
This is the kind of hard-working journalist with integrity I'd have expected Matthew Keys to be.
He's not one.