Other mistake: In the 'Valiant Hero' ending to 'Completing the Mission', Charles is killed when the space station he is in explodes. Somehow, his headphones survive the explosion that the space station and Charles himself didn't (they are found on his grave at the end).
Suggested correction: Who's to say that the headphones on the grave wasn't a copy or a similar one of the one he was wearing? We never see anyone return to where the ship exploded, so we don't know anything, hence it can not be considered a mistake.