Of course it's fair to hold "witnesses" and "reporters" responsible for the consequence of what they say.
The person responsible for the speech that was reported are the people speaking; the person responsible for the reportage of the speech is the person who did the reporting. The former resulted in a woman being uncomfortable while the latter lost a father of three his livelihood.
You've got a problem with apposite context and proportionality. A techie at a conference making a dongle joke is not a gay biker in a bar telling anal virginity jokes, is not the frat-boy gang rape of an unconscious teen girl.
True, they are all "bad things happening" - but that is such a large category that to act as if or argue any specific response is justified due to it belonging in that category is likely to lead to damaging over-reactions.
In the context of corporate public relations and harassment lawsuits in the workplace, which became relevant the second the tweet was sent, what she did was an extremely damaging over-reaction - which given the woman's background and role we can conclude was committed with malice aforethought. Your entire argument is based upon wildly inappropriate contextualisation.