If losing one executive at a 200+ employee company "ruins the company's culture and causes [that company's] downfall", then that company and that executive have

If losing one executive at a 200+ employee company "ruins the company's culture and causes [that company's] downfall", then that company and that executive have been doing it wrong! Regardless of the facts of the case and whatever damage it may have done to GitHub's culture, if this incident and this individual's departure are enough to cause GitHub's ruin and downfall, then that's evidence of an absurdly fragile company and culture.