The employee, as a white male in tech, is absolutely morally right to use his privilege to call out other powerful white males for their silence.
And make no mistake, silence is complicity. Many smart philosophers have written about this, see MLK Jr. or Maya Angelou for more.
This is the core of being an ally. Use your privilege to make the hard ask from your peers that a less privileged person, who is decidedly not a peer, cannot.
FB, on the other hand, is also right in a different sense, to maintain internal expectations that singling out colleagues with your political opinion in public is ineffective at best and toxic harassment at worst. FB are signalling to the rest of their employees what behavior they will not tolerate.
In the end, this employee leveraged awareness several orders of magnitude more than had he not been fired (and will likely easily find a new job) and FB protected whatever they believe their culture to be (and whatever other HR lawsuits they believed themselves to be at risk for).
As for Dail's victim, you don't know whether he has or hasn't helped in his own way. This Dail guy wanted to coerce a coworker to do something that RISKS HIM GETTING FIRED. He said no to Dail; this doesn't mean he hadn't or wasn't willing to help.
I don't like FB and I hate Zuck's stance, but no company would allow someone like Dail to continue bullying coworkers and creating a hostile work environment. I wouldn't be surprised if he already had a list of prior complaints. HR doesn't usually fire people based on a first-time offense.
If you are ever in charge of fundraiser or are looking for people to join a worthwhile cause that you support, try to understand that you'll gain more allies if you're not shitting on & shaming people to do what you want.