I once accidentally "ragequit" a Killer Instinct ranked match because the Kinect thought I transformed into a completely different person and switched me to my friend's XBL profile, which sent me back to the main menu. It didn't see him and think he was playing. He was in his own home 200 miles away at the time, and nobody else was even in the room!
SuperNiceDog didn't have to reconcile his name... But Dauntless Hunter is now MrGreenonion