I think the problem is that we are arguing two different things here. You are arguing that Martin committed a crime and acted like a douchebag. I agree 100% with this. I am in no way trying to defend Martin's copyright infringement. What Martin did was wrong and Zed had every right to ask him to take down the book.
What I am trying to argue is that Martin wasn't being malicious, he made an honest (albeit stupid) mistake. It sounds like he believed that Zed would be thrilled that someone was extending LPTHW to Ruby and didn't realize he was committing copyright infringement in the process. To be clear this in no way excuses him from the consequences.
I am drawing this conclusion from the following: Martin acknowledged Zed's authorship and that Martin contacted Zed to let him know about the project. I am also speculating that Martin was ignorant of the licensing and assumed a permissive license. LPTHW is distributed for free (as in beer) and Zed has released a lot of other things for free (as in freedom). It's not that much of a stretch to see how someone could assuming that this "free" book was open.
Zed had every right to ask Martin to stop writing the book. I don't feel that calling Martin "classless" was called for however, given that Martin seems to be a Zed fanboy of sorts.
For some reason you seem to think that I am arguing that Zed is 100% in the wrong. I am not. I'm just saying that both acted in a manner that is unbecoming of civilized people.
As an analogy, let's say I wrote some fan-fiction based on a story I really like. In the process I copied too much of the original source. I publish it on my blog and e-mail the author of the story a link to it, thinking that the author will excited to know that she inspired me to write and will maybe enjoy seeing a different take on her work.
Instead calls me classless for not writing my own original story and tells me to remove it from my blog.
While she has every right to ask me to remove it considered I'd copied too much of the original work, I wasn't trying to offend her - just the opposite in fact!
Was I wrong? Yes, of course. I posted her copyrighted story on my blog. Was I classless? I would argue no - my intent wasn't to write an original story, but to extend a story that I loved.
At this point, I might be tempted to call her out for calling me classless (which I really shouldn't do, and Martin did), but it's easy to see how I could feel that way. A simple "please remove this" would have been sufficient, I would have realized my error and I wouldn't feel bitter about the exchange.
TL;DR - There is a difference between being ethically wrong and legally wrong and two wrongs don't make a right.