He never struck me then, or in any interview or write up since, that he's impulsive, or prone to taking actions like what he's done to Twitter, in a cavalier way. He saw something bad and thinks something should be done to address it.
He likely made that decision because the culture at Twitter is as bolloxed as he states (maybe worse), and that it's one thing to fire a guy, but to do so to hide damning truths, and expect that person to just accept their fate AND let you get away with it without a cost is in this day and age, a farcical hope. Your "Mudge knows the implications of "whistleblowing". He has been a security consultant and even testified to Congress. He's not some noob that doesn't understand security or how systems work together to provide services like disclosure to FTC. The idea that Twitter PR can pooh-pooh away his concerns is shockingly stupid." is spot-on.