I had one that did that just the other day too. It pipped at the wrong end. It unzipped, hatched out and seemed just fine. But it was not. Something was wrong with it's eyes. I don't know if hatching from the wrong end effected its eye or it hatched at the wrong end because it couldn't see. Either way, sadly, it died yesterday. I do hope you have better luck and I wish you and your little chick all the best! I suggest keeping an eye on it really closely for the first week or so to make sure it's eating, drinking, pooping and active like the others. IMHO the most important part of keeping an eye on a chick is after the first 48-72 hours when they have used up and digested all their yolk and need to find food and water.
Mine did hatch, but I think that there is something wrong with it's legs. It's foot isn't curled, but it's thigh bones both stick out funny. I hate when this stuff happens!