Dunkelzahn = Bad Guy? Options

[TheBigDLives]

So, while one of the things I love most of all about Shadowrun is one's freedom to interpret events as one wishes and to be exposed to many different opinions on current events (at least in the first few editions), I have always thought of Dunkelzahn as, well, a pretty good guy, for a dragon. Everything I've ever read about him (and I've read quite a lot) seems like he was at least somewhat dedicated to the common weal. All things considered, I tend to think of it as a good thing that he walked the Earth.

Yesterday, however, I came across something very upsetting to me while reading Dragons of the Sixth World. Captain Chaos prefaces the section on Masaru, another dragon trying to cultivate a positive image, with these harsh words:

"Dunkelzahn, as good as he seemed, was able to pull the wool over everyone's eyes. It won't happen again."

Ouch. If Dragonslayer or some random git said this, I wouldn't mind, but Captain Chaos was generally very moderate and well-informed, and even, in other works, expressed approval of Dunkelzahn's activities. What on Earth is he talking about here? What did Dunkelzahn do that was so terrible that Captain Chaos would say something so awful about him six years after his death?

I must know if I'm missing some crucial part of the picture. Please help if you can.