This isn't an accurate summation of how defamation works, and Jew Wario wouldn't have won a defamation suit if he filed it. Also, what you say about former employers isn't true—they certainly can give out the fact of why and how you were terminated. They usually don't, because it is generally better to play it safe, but you're just plain wrong to say that they can't. What's even stranger to me is that you bring that up while you directly state Justin wasn't an employee to begin with.
Any lawyer worth his salt can tell you that defamation is by and large immensely unfavorable to a plaintiff. There are so many potential ways that the people at Channel Awesome could have made a statement regarding Jew Wario's behavior at conventions in a way that wouldn't be actionable or easily defended with a good faith exception. Unless Mike literally put in the statement that Jew Wario was a confirmed pedo-rapist, you'd have a hell of a time winning a defamation suit.
Here, I'll even give you a quick example of how easy this would be:
"Channel Awesome regretfully has decided to cut ties with Justin "Jew Wario" Carmical after complaints about his actions at various conventions. We have been given reason to believe that Justin conducted himself improperly with his fan-base and engaged in behaviors that we at Channel Awesome cannot condone or defend."
Defamation is built on the idea that you're tarnishing someone's reputation by making an untrue statement. If you don't have an untrue statement, you don't have defamation. If it's true they received complaints about improper conduct, and that's where they terminated him, there's no room for a suit.
My bet, however, is that Michaud has a lawyer that plays Call of Duty all day and can't be asked to draft up a three sentence statement detailing their reasons for terminating Justin in a legally unambiguous manner and would prefer to just quietly let the whole thing go because it means less work.
