Spinach in teeth could happen to anyone. Flaunting of ignorance... well, it probably does happen to everyone, but I think "he who is convinced against his will..." applies. What was the context? Did he make this pronouncement to a group of people?
Basically, if one wants to become the type of person to go about correcting people's mistaken notions about grammar, it's probably a good idea to have a book or two that you are then willing to stick to in the future where you can show people. I happen to have a whole shelf where I could go and look stuff up depending on what the desired outcome of the conversation is. :devil: I'm just sayin'. It's a rare argument that can be won with "Language is an organism; words are neither good nor bad, they simply exist."
Boy that last phrase was hard to put. Also, I've never had to open a book with someone. In general, the knowledge that I could results in people not questioning me much. It's weird, because we question each other a lot here, because we're mostly languagey types, and hyperliteral ones at that. In normal life, people find me scary.
Part of what I love about my job is that my boss is very literate, and I know that he values my skills. I just realized that.