When you append, "Or I will leave" to a request and the company isn't interested in your request, you're resigning. You can dress it up in fancy language, but that's the bottom line.
Or did I miss something about this story?
[1] https://twitter.com/timnitGebru/status/1334364735446331392
An any rate, this seems to me to be an excellent case study in ultimatums. Namely, don't give one to someone more powerful than you.
She expected she would have to leave after her ultimatum. She was fired for a different email.
That's not toxic, that's anger. One angry incident, justified or not, does not make the case for firing a "toxic" employee.
1. Absolutely refusing to update her paper with feedback from a colleague - the whole purpose of the internal review
2. Demanding that Google reveal who gave her critical feedback - presumably to attack them in some way
3. Sending an e-mail to her superiors/colleagues, making ultimatums and threatening to leave if her demands were not met
4. Sending a message to a group at Google, telling them to abandon any attempts to help Google with diversity initiatives and instead start attacking their co-workers
5. Publicly blaming Google and saying that she was "fired" for an e-mail. She was relying on information assymetry, knowing that Google would be hesitant to respond fully to all allegations
What about the paper trail she left on Twitter?
That's not being professionally assertive.