But she was explicit in saying no one even asked if anyone was watching. Instead, each person in succession walked in, recoiled in horror, and decided to flip the channel without a word. One person doing this is unexceptional. Two? Less than chance, but possibly coincidence. Three or more, however, suggests a gestalt of in-group sports dickery existed around her.

It's inferred by people being in the area to laugh at everyone picking up the remote.

You know what, the story also doesn't tell us that nobody was on fire at the moment.

When you walk into a shared TV viewing area with people in it, and there is something being shown on TV, even if it looks like nobody is looking at the screen at that moment, you should still ask before changing channel. Social fact. If it looks like nobody is watching it, you can soften it a little by framing the question as "Is anyone watching this, or can I change channel?"