Honestly alot of the time if they can't hatch on their own they have issues. I've saved a few that got shrinked wrapped. I also saved some with wry neck and intestine problems all of them died within they day of helping them hatch. I now leave them alone for the most part.
Temp might of been to high. Also if it's a bantam size it's not unheard of. I would be a little weary if it comes out with defects to be honest. Also the egg might have been incubating if stored in warmer temperatures.