You know, I had to think about both of these for a few seconds. But the simple fact is that as a public figure, and the owner of any company, be it large or small, you have to represent that company. Now, nobody has to be perfect, but when remarks like that are leaked, no matter where you're at, your company has the right to fire you. It's simply the fact that you are causing potentially enormous damage to your company, in a way that cannot be defended by saying "hey, it's just my opinion". So I'd say that he's a victim of being taped without his knowledge in his own home, but that doesn't remove that fact that the statements, even if illegally acquired and spread, are still hugely damaging. That's simply enough to throw someone out.
As for the community manager, he is one, if not THE most important face of his company. He should know that his most important job is actually to represent his company, so he should know that everything he says publicly outside of his role as community manager will still reflect on his employer. If he had slightly reworded his tweet it could've maybe been different, but he openly declared sterling a victim. Just not smart at all.
It's actually fairly often that these PR types and community managers slip up by making an inflammatory comment somewhere, does anyone know why? Is it because they need to vent, or because they forget their position? Maybe because twitter doesn't allow someone to reflect before posting or remove a tweet easily? I'm thinking it's all of it.