Yes, I know, but I'm talking about where anyone here said it. My point has to do with the relevance of his response to what I'd said in response to his OP. So he is tilting at windmills when it comes to engaging in discussion.
Look up poisoning the well, peter, you use it inappropriately. It is used prior to anyone responding, not in a response to what someone says. The idea comes from poisoning a well before someone can drink from it, not ineffectually after.