I don't have an example for you. I see another left hook coming your way unexpectedly and that is from the term "genocide." It's fairly new. It was coined during WW2. And people still argue about the definition. We have killed each other for time immemorial but we didn't have that label that stuck to slap onto the most egregious cases. So anything before the Holocaust is given the label after the fact. And that will have some historians at the ready contesting it. So most genocides are contested not because they don't want to admit a lot of killing was going on. But because they cannot agree on what genocide means.

They hold ten-year trials in The Hague to figure out if a Milosevic or similar asshole is guilty of it. There is wiggle room in the definition. Were enough people killed? Was it targeted enough? And other distasteful questions.

We talk about genocide like it's a fixed term and everybody knows what it means. But it's more in that "I know it when I see it" category and the resulting wiggle room will make any argument you're having harder. You can't get to the slam dunk of your argument when your opponent withdraws from it on this technicality.