Wow Steve, I'm not really sure what to say about your boss/boss's, except that one of them seems like a dick. To fire you for something like that seems without merit. To blame you for stealing all of a sudden after this situation seems opportunistic. I am a "boss" myself at work and man, there is no way I would have fired you over just one incident. After all, you did let one of your bosses know what you did which shows integrity. It is very sad that you showed initiative, then got burned for it.
I am truly sorry to hear about that. What are you going to do now?