<human>: America, Northeast USA

Background: I used to make a good deal of annual money, but then the business I work for went under on December 31, 2013. I was married in Dec 2013, and moved full time to the suburbs. A lot of my deferred compensation came due in 2014, and I had a massive tax bill.

My accountant filed an out of state return, but according to her, a "software error" checked an in-state return for my commuting city, even though i don't live there and live in another state (that was where my employer was located). She then said essentially, "My mistake, but you appeal directly and fix it." This is not a small mistake-- it's just shy of $30,000.

My appeal was denied. They are now saying "We will fight this for you. Sign a POA, and we will go directly to the state on your behalf." I am saying, front me the money I'm owed due to your error, align our interests to get the money back and a proper filing, and let's proceed.

The accountant's response was "I cannot make you whole, I do not believe malpractice occurred." Very cagey guy, if you look at how he constructed that rebuttal.  

He is confident I will win the appeal, but won't answer my question of "what will you do to make me whole if I don't win the appeal?"  

Any advice on how I should proceed here? In my business, we "go to the tapes" and when you make a mistake, as bad as it hurts, you make the other side whole. This guy -- who has been a family friend for 30+ years -- is playing CYA all of the sudden.  He knows his firm screwed up -- and filed a tax return that I did not sign off on (I signed off on out-of-state), and they did some sort of hybrid due to a self-admitted clerical error.  

Any advice on next steps?  Do I hang tight and give them POA and let them challenge, or do I hire an attorney/alternative accountant to bring suit/re-file?

Can you summarize the given text in a few sentences?
<bot>: Accountant filed wrong state tax returns, admits mistake, says "you fix it" and only intervenes near the 8th inning.