After asserting, "We are all responsible for what happened in Orlando," just in case there was any doubt about the title of the post being imposed by an editor or something, Prof. Rees provides a brief anecdote about a colleague who told him that she had recently turned off her television because she saw two men kissing.
He then gives us his thesis:
I am responsible for what happened in Orlando because I should have confronted my friend’s homophobia directly and told her that I found it offensive. Every anti-gay joke we listen to silently, every homophobic slur we fail to counter, every hostile act against LGBT people we witness without standing up and speaking out makes us complicit in what happened in Orlando.It does not seem to matter that Prof. Rees' story does not contain an anti-gay joke or a homophobic slur. In fact, his characterization of his friend's decision to turn off the TV as an act of homophobia seems like a real stretch. I've lost count of the number of times I've turned off the TV because I wasn't interested in watching unnecessary heterosexual sex scenes. But none of that really matters. What does matter is that Prof. Rees "found it offensive" and did not call it out. And because of his failure to do so, "We are all responsible for what happened in Orlando."
Prof. Rees goes say that we are responsible for Orlando because he did not do enough when Donald Trump made bigoted statements about Mexicans or suggested a temporary ban preventing Muslims from entering the U.S. We are also responsible for Orlando because Prof. Rees has not written to his elected officials about gun violence.
In the context of terrorism, you've heard the statement, "If you see something, say something." Evidently, a similar sentiment is fueling our contemporary call-out culture. If someone says something you find offensive and you do not call them out, you are responsible for all our social ills. If you do not participate in attempts to punish others for what you regard as bigotry or shape their behavior so they are less likely to express views with which you disagree, you are "part of the problem."