A number of years ago I had a client do some stupid things that cost them a lot of tax dollars without consulting with me before he committed the acts of stupidity.  I worked on the return and I called him up to tell him how bloody things were looking.  He got belligerent over the phone, but I kept my cool during the conversation.  Immediately after the call I typed a nice professional letter telling him to hit the road, put it in an envelope and dropped it off at the post office ------ all within minutes of ending the phone call.  I had never done that before and I have never done it since, but it was quite refreshing.  Life is too short and tax seasons too long to deal with difficult people.  Tell him "hit the road Jack".  Trust me, you will feel much better.