I think he is a solid coach but he was not wrongly fired. He tried to take over that Raiders organization and tried to make a Power Play, then came a little unhinged and was saying bizarre stuff at his last presser. He also completely lost the team and things were really ugly there in Oakland as they collapsed at the end.
Then apparently he floated a rumor to Michael Silver about how he got fired because he knew that Al Davis used to treat his kid like an idiot, insult him, etc. Silver did a despicable hit piece on Mark Davis just a couple of days ago.
He might be a decent coach but the way that thing went down in Oakland, no thanks.