It's all in the delivery. Instead of acting like a fifth grade teacher using your red pen when you could have easily just said "Actually, I think the airing you're referring to was the episode's rerun that occurred the week
before the 25th Anniversary Special."
Regardless of self-proclaimed dorkiness about airdates, you'd likely never correct someone asking for your help in a manner like that when speaking face-to-face...why does it need to happen here?
Y'know, if the guy I was actually replying to isn't bothered, I don't think I'm gonna worry.
...which means the behavior will likely continue when interacting with others.
