My money's on being caught red-handed at copyright infringement. Plus an unhealthy level of entitlement (I'm a fucking Engine Yard programmer for fuck sake.)
The Engine Yard comment was meant to be taken as "I use your stuff (mongrel) and respect you. I had no intention of wronging you."
As for "being caught red-handed" it's a matter of intent. Martin didn't mean to wrong Zed, he was inspired by Zed but ultimately messed up (by assuming it was okay to modify the text).
