the secret is that it doesn't matter whether or not deroir was condescending, or whether or not price was justified in getting upset, or whether or not either of them misread the situation, or whether or not either of them misread the developing social mores surrounding twitter.
all that really matters is that the community was upset because of Price's comments, and so she was axed. the community was also upset with Fries for sticking up for her, so he was axed too.
it is a view purely from the bottom line, a view where it does matter whether or not anyone was justified - it would have happened regardless of whether or not it was "deserved". but questions of whether or not the firing was "deserved" govern the amount of backlash against ArenaNet and against those who whipped up the frenzy that ArenaNet responded to.
the lesson for developers is exactly as stated - unfortunately, they have to be wary in their interactions with customers because the harassment mobs can and will aim to get them fired. you are never off the clock no matter how much you may be reassured that management loves your "righteous talk of truth to power". the company has no real motivation to shield you from harassment unless you suffering from it may come back to impact them in a negative way, and while in some cases you may be able to trust the good will of others in the company, often times the bottom line comes first.
abstracting away the surrounding context to this does appeal to people's propensity for the just world fallacy and the tendency to see bad outcomes as "deserved" to maintain that fallacy, and so thus this incident is plucked from the surrounding context of how the video gaming community treats not just developers, but everyone involved
even though the context wouldn't influence the result, it is still erased because it would influence how people feel about the result.
personally, i think recognizing this context is useful from the perspective of recognizing that these harassment mobs clearly exist, clearly take publicly visible actions, clearly state their motives, and are clearly having an impact. that also has nothing to do over whether or not anything specific about this situation, but about the state of the community and industry.