My advisor escalated things after not getting a coauthorship he did not deserve
How are 'attitude problem' and not obeying your adviser a 'crime'?  In my university, there is a 'co-authorship policy', which clearly states that any co-authors must have made significant intellectual contributions.  If such a policy exists at your university, I would bring it to support your case.

If you're fronting the committee because of supposedly poor progress, then I would gather as much evidence as possible to support your case. For example, your communication with your external adviser, papers published, etc.

I suggest you change the supervisor. The situation will definitely get worst because it looks like the internal adviser is unethical.  He/she will 'burn you alive'.