Actually, Gagarin flown with old superior in rear cabin.
That superior was having controls and while performing maneuver had a heart seizure, plane went out of control, ground dispatch ordered to eject. Trick is - that plane doesn't had force-eject feature for both pilots, so that old officer would die in crash, unable to eject on it's own. Thus Gagarin stayed, trying to save them both until the very last second.
Please respect the hero's memory and do not repeat accusations like that.