Hah. This guy replied (then immediately blocked me):

We are only talking about social media, and we fundamentally agree that that usage was literal. But thanks for showing you can't back up anything you said and provide alternate social media, or any news media forum, to match those

— Burton Fisher's tweet

So Glenn’s usage wasn’t literal at first, then it was literal. Also, those were their goal posts, not mine. They wanted me to back up things I didn’t say.

Their initial reply didn’t seem to have that much animosity, so I presumed good faith. I guess this is another lesson in determining when something is worth replying to or not.