I just had to explain to someone yesterday "No, you just said not-A as evidence of B. You can't do that and say A is evidence of B. Because if you say both, that means A or not-A has nothing to do with B."

"You expect me to go get more evidence."

"No, I expect you to have evidence already to make that claim."

I'm not entirely sure I convinced, but it's about as compact as I can get it in small words. "A" and "B" were the actual things we were talking about.