sorry to say it, but it looks like rot below the broken side branch down below. maybe best to recut, callus, and repot?

It does look that way. See if you can draw white sap in that area by using a pin. Maybe it's only sunburn.

PJ,
You said it was still hard @ the area where there were wrinkles? If so did you water root in a glass jar, or clear cup by a sunny window? Try to prick it with a pin in the wrinkled area, if white sap comes out it may have gotten some kind of sun/heat burn. If black juice leaks out its prob rot. I noticed the wrinkles are right below the cut mark. If its rot maybe have come from there, moisture entry point (should have sealed it before rooting).