Similar thing happened to a recent soap of mine, neeners... partially gelled, overheated a bit from the heat of the sun (I had to bring it home with me in the car as I made it somewhere else) and then it got a partial gel from the outside in as well as the inside out - I CPOPed the bars to fix it but there's still a subtle line where the soap didn't gel. Don't wanna cook all the lavender out of the soap!
I rebatched my partially gelled mint soaps because not only are (were) they very ashy, but the mint smell is gone because I was stupid and left the bars curing on a sunny windowsill instead of in the basement. Added more peppermint and some rosemary, too. Also added a bit of sugar to boost the lather and a little salt in hopes of making it come out of the mold faster, not sure if the salt trick works for rebatch soap though. I actually had to rebatch it again because I added way too much water the first time, now it seems to be hardening nicely.