Just one question Paul. What did the root and crown area on the second plant look like? Any signs of pests or disease?
I'm with Greg on the first photo. It would be good to cut off any unhealthy tissue lest it continues to rot. Leave it out of the soil for several days until it is completely calloused over before re-potting it. Will it is drying out keep it in a protected area away from sun and hot/drying wind.
