Either form is cromulent as both are historically accurate.
AFAIK, "Him" has been the accusative (subject) form since at least Old English. https://www.etymonline.com/word/him
ETA: I generally don't bother "correcting" the grammar "mistakes" that native speakers make (like "My dad and me did X"); but if I think it's pretty clearly a non-native speaker, I'll correct them, because that's what I would want someone to do for me if I were speaking in their language.