What are you hoping to accomplish by highlighting this particular tweet? What does this have to do with the incident at PyCon? What does this have to do with determining the facts of what happened at PyCon?
Even if you disagree with this tweet (which i do), aside from the obvious character assassination, what exactly are you asking us to infer here?
That in this situation she's playing a victim when she's actually the one with the power. Granted, old tweet.
She has a twitter account? Or because she works in developer relations for a startup? Or because she's got two X chromosomes? Or because she's black?
Edit: changed wording.
Not trying to be a jerk - if you feel the jokes are somehow unique or offensive. Most people just don't see it that way though.
I personally am not offended by the joke nor do I think they are clever or unique, but saying that they don't matter because they're the status quo is a really weak argument and it speaks to the lack of progressive thought in this community when it comes to diversity.
The tone of conversations between other males often repels me, but the reaction to calling them out for it is worse often then simply putting up with it, as Adria Richards is experiencing. The focus is shifted to examining the complainant rather than truly evaluating the matter at hand. It's extremely unfortunate to witness or experience and is undeniably regressive in my opinion.
A direct result of the tweet is the termination of the employee. Without the tweet the parties involved wouldn't be identifiable, and no one would have lost their job.
Is the joke a direct cause of the firing? No. Many subsequent actions must take place to get from the joke to the firing. The joke isn't even required in the sequence of events. Because tweeting a picture of someone and labeling them a sexist is enough to get them fired from a certain employer.
It's well known that political activists are quite more able to see the enemy that "laymen" - eg. when FOX Newsers call something or someone "communist" for an example from the opposite end of the spectrum.
Implying that someone should be vilified for holding a political opinion you disagree with is fairly horrible and remarkably similar to the thing you're (and I with some caveats) disagree with Adria for doing in the first place.
Racism, sexism, etc. are characterized by the desire to damage a certain group while propping up another by making broad-scoped and baseless inferiority/superiority statements, often followed up by aggressive actions. It's not necessary for one group to be "in power" for this to happen. Racism in cases where minorities are the perpetrators is exactly as unacceptable as in any other circumstance and people who defend that should be called out for it.
In short, and conveniently looping back to the actual topic at hand: behaving like an asshole is never OK.
When one person says "black people can't be racist" and another person says "black people can indeed be racist," they are using the word two different ways and meaning two different things. It has derailed more threads than I care to remember.
1: Culture, Motivation, and Learning: A Multicultural Perspective edited by Farideh Salili, Rumjahn Hoosain, p. 327-328