I can't think through all the flaws but "criticism of the government is protected speech for employees" broadly seems achievable, which of course has tons of annoying details like "when is an employee speaking for a company vs for themselves, are personal twitter accounts an employee's own speech" or "what is a government entity" or "what is criticism" or "what is an allowed disciplinary response to grey areas" and so on.

This wasn't even 'criticism of the government' at the end of the day, it was wholly unprofessional communication and blatantly rude.

Honestly I cannot believe people are bending over backwards to support the actions of the blog author.

It pretty clearly is criticizing the DoD and it's representatives for 1. killing people (probably in a general sense) and 2. participating in and advertising themselves at a tech conference while doing so.

Is it the profanity that puts it over the line? Profanity is often how we express that a feeling is extremely strong, and in the context of criticizing the government it's a pretty time-honored tradition given the power imbalance it has.