grammar - recollection

something has been bothering me for...uh...i think about 2-3 weeks already. and its about flaming. not online, but in real life.
me and my friend were doing a debate thing against other groups. at the end of our speeches, this girl from another group yelled at us
"YOU FAIL YOUR ENGLISH AH?"
i find this very very very very ironic. her exact words, "you fail your english ah?" itself is actually grammatically incorrect. and she was accusing us of "failing our english". i presume that it's because our speech was too profound for her, and she couldnt understand most of it, so she assumed that the we werent speaking proper english. or something like that

okay thats all. thankyou for reading/ignoring/whateveryouhappentodo my rant

tata