Most of us Canadians here were able to see that Nerd Girl had never been in Canada because the way in which she interpreted our political spectrum was not true to our country's politics. It's not a value-judgment but a truth-judgment: she's clearly an outsider in the way that I am living in the U.S.: I have markers that give away my ignorance because I'm not an insider.
You're the one saying it's universal, and ironically, you're the ethnocentric while trying to include everyone in this discussion equally. It's a conclusion predicated on a false assumption that we're all equally able to discuss this subject matter. We're not. She hasn't done enough research to know why she's an outsider, but insiders can mark her as an outsider because she's missing cultural knowledge. Just like people can mark me as an outsider where I am.