Fic Pet Peeve Inquiry

[elleflies]

So, I keep seeing this phrase pop up in fics over and over and over again. It always goes something like" "so and so was sat in the chair at the table." Now, personally, that doesn't sound right to me. I keep thinking that for it to be grammatically correct it should read something like "so and so was sitting in the chair at the table."

Am I crazy for thinking it's a bit off? It's just that I keep seeing that particular turn of phrase, the sat vs. sitting, everywhere.

I think I've got a pretty good grasp of grammar, for someone who has a Bachelor of Fine Arts and hasn't taken an English class in God knows when... but please, enlighten me. Am I crazy or am I actually acting crazy for a valid reason?