The pommel fallacy
When someone in an argument attempts to deny your argument by nitpicking a small mistake, such as a mis-pronunciation or typo. Named after the famous "end him rightly" meme, where a fencing opponent throws their pommel in your face as a distraction.
"That's actually a sea lion, not a seal, therefore you're completely wrong about everything" "Bullcrap, that's The pommel fallacy"