Other mistake: Arcade version; in one of the cutscenes between fights, Geese asks his henchman Ripper "Hey! get the information from him." From who? What he really means, and that's what he says in console ports, is "Hey! Get more information on him!"
Other mistake: In the SNES version, the line "Dude! Geese is calling you! Come with us!" is spoken by nobody onscreen (there's no artwork for Hopper and Ripper, Geese's henchmen), nor there is any visual hint; unless you played already the arcade/Neo Geo version, it looks like it's still Joe talking.
Character mistake: Playing as Joe Higashi, one of the preliminary cutscenes with Geese has him say "I wonder if Joe is Hurricane upper cut Joe." "Uppercut" is one word, not two.
Other mistake: The intro crawl of the SNES version contains various flubs; it calls the tournament "The King of the Fighters", when it's simply "The King of Fighters", "Southtown City" when it should be "South Town", and the final sentence "Only through deadly combat can you be crowned the King of the Fighters..." is just odd.
Other mistake: The very last screen when you play the arcade and you manage to finish the game features the logo of the series and the message "Congratulation."
Other mistake: The SNES version of the game misspells the owner of Pao Pao Cafe, Richard Meyer, calling him "Richard Myer."
Character mistake: One of the cutscenes of the game happens between the 5th and 6th round, Hwa Jai and Raiden. Geese, the main villain, botches the name of his henchman saying "Riden." (Fixed in the SNES and Genesis version, still in the various versions on Playstation).
Character mistake: Both Geese and Andy are experts in martial arts and come from similar backgrounds (Geese and Andy's father trained under the same master), but Geese says in the cutscenes Andy is using "weird kung-fu", and Andy mentions in his win quote "Japanese Karate."
