In my experience IF the rest of the hatch was fast and clean, and you have a straggler that is 2 or more days behind the others, and you help it out, it will die anyway-not because you helped it because you think its stuck in the shell, but it has some other problem and is too weak to hatch-thats why it didnt hatch. On the other hand- IF the hatch was very drug out and not very successful, there was most likely a temperature issue and human error that is preventing the chick from hatching and if you help it(provided it is READY to hatch) it will be fine and healthy with no problems.