Very similar incident happened to one of our Flight Attendants the other day when she finished the pax safety brief and began her final cabin check prior to taxi. She was informed by a passenger of aboriginal origin that the use of the English and French in the brief was an "insult to her race and language and that every time the flight attendant or flight crew used English it burnt her ears with hatred she felt towards 'Canadians' for the hundreds of years of oppression."
Meanwhile the 30 or 40 other people on the airplane all from the same community had no problem and were happy to get in the air and actually apologized to our Flight Attendant for their friends actions!