I admit, I wasn't expecting such a response. But let's take it point by point, shall we?
1) He should have kept information from his boss
a) No, he shouldn't. He works for the organization, and the organization put someone else in charge. Them are the breaks. I will grant you that his bosses are almost as liable for not making him document things ahead of time. Further, if it really did shake out the way it's claimed ( he was fired and then asked for the passwords ), then there's nothing criminal about that.
2) You shouldn't document passwords
a) Maybe in a small mom'n'pop shop. In the real world, real admins aim to protect the network. That includes from you dropping dead, or more likely, moving on to greener pastures and forgetting to tell someone something before you go.
3) Professionals are anyone who gets paid to do a job
a) A professional is anyone who takes pride in their work and does the job right. I don't grant that title to a vast majority of IT workers out there; they are unreliable ( the afore mentioned ones who don't document passwords ) and untrained. Essentially, kids playing with their toys.
As an IT professional, I know the network doesn't belong to me ( as child's apparently didn't ). I know my purpose there is to increase productivity through the use of IT services and equipment. To that end, I do everything in my power to safeguard that primary purpose.
I do not throw a fit like a child because someone I didn't like got promoted above me. Hell, I don't even care if the only use they have for a keyboard is to drool on it. If they ask me for a piece of information that I failed to document ( which is my mistakes anyway ), then I give it to them. To protect myself, I will get everything in writing, so when the idiot deletes everything on the SAN I have documentation, but that's it.
But let me reiterate; I agree with one premise. If he was let go before the requests were made, it's not criminal for him not to give it up. As an employer, I wouldn't touch him, both because he is being stubborn and because he didn't document, but it's not criminal.
Were I the City of San Fran, I'd fire his handlers too for being so incompetent as to let someone like Childs bring the city to it's knees.