So if I buy a safe secretly with the company credit card, and fill it with material I completed on company time, and they fire me, I'm not legally obligated to tell them the combination to the safe?
The fact that you did it "secretly" might get you into trouble- using a company credit card for unauthorized purchases is fraud. I suppose you could argue the kid defrauded the company by spending his time programming rather than doing data entry. I don't think that would be as easy to get a judgement for as credit card fraud.
If your job was securing their stuff, which was before in piles on the grass outside the offices and they fire you for putting it in a safe instead, then probably not. You haven't stolen anything and they fired you for doing your job too well. All safes are openable and they opted for the hard way when they fired you. Would probably depend on the court though.
