Might you share an example of what leads you to believe that Comey is capable of acknowledging when he's gotten things wrong, changing course, and moving on? I've never had the chance to meet him but even General Hayden's remarks on Comey seem less glowing than yours. For example, while Hayden does describe Comey as a "very competent" and "very honourable man", Benjamin Wittes, in a conversation with Hayden, described some "not so veiled hostility to Comey" in Hayden's recent book [0]. Hayden has, in my view, been able to weigh the national security benefits on encryption alongside the national security risks. I've never once heard Comey speak with any degree of clarity or comfort on the issue, and has instead doggedly pursued his goal of ensuring the FBI's access into content data. Thus, I've described him as a 'one-track-mind kind of guy'.

Well, I'm not sure if my comment about "the worst kinds of cops" is necessarily hyperbolic or even emotional, but I can see how it does make having 'purely rational discourse' more difficult. Surely, a singular focus and unwillingness to consider the validity of alternative perspectives is not unique to some members of the law enforcement community, but I think that the shorthand I employed does cut to the core of my understanding of Comey; He doesn't understand this issue as well as the technology experts who, virtually uniformly, disagree with his position on crypto.

[0] Hayden did rebuff that characterization, though I think the public forum might have had something to do with it.