BigBella is right. They just crap out sometimes. When it comes to Cephalotus it's better to underwater than to over water (in general) and when they do this, I'd let them dry out a bit. They really remind me of Cycads when it comes to their watering. BTW, I recommend deep clay pots because of their moisture preferences.
If it dies, it dies. You can replace them, there is a learning curve. Sometime they die for no apparent reason. I also highly recommend using Trichoderma.