I feel like I'm missing something here. I read the emails and their responses seem perfectly acceptable to me, I am not picking up an arrogant or confrontational tone and think they did their best to answer the issue. The author asserts a copyleft license to the work and fully expects Amazon to be 100% compatible with it (one could almost say arrogantly so) and does not, in my opinion, assert exclusive publishing rights of the work. Amazon state they are not confident author holds the exclusive publishing rights and that this is not acceptable on the Kindle Store, linking to the relevant policy guideline. As someone else has pointed out, the author is also not the customer here, they are in effect negotiating a business deal with Amazon, Amazon do not need to tip-toe around the issue. I think the author was a little bit over sensitive here.
If I am missing something here please fill me in.