However, I'm not sure how his academic discussion about OPSEC "pimps an image" for his 0day business -- wouldn't security researchers writing 0days not really need the advice in OPSEC For Hackers since they are still acting legally?
Your own government isn't your only potential enemy.
True story: A friend of mine works for a large defense contractor. He's done a fair amount of foreign travel to support projects on foreign soil. Not clandestine projects, they are fully above board with the cooperation of the host countries, but as Kissinger said, america has no permanent friends or enemies, only interests. (Kissinger's a douche, but he's right about that)
The result of all his work travel is that he's made it onto spear-phishing lists at all kinds of national hacker groups. His employer's IT security has had to put his corporate email address in a special group that gets extra scrutiny because of all the attacks directed specifically at him.
The Grugq addresses this issue by recommending that one set up an entire fake persona before doing anything, and then doing all the activities "in character" as that persona. If you stay in character, then even making the types of mistakes DPR made would only lead the authorities to the persona rather than yourself.
Granted, this video didn't exist when DPR made Silk Road...