His tail tip looks fine to me. It's very possible he might have retained a few layers of shed on his tail tip that finally came off. I've had that happen with one of my corn noodles. It would have felt hard and dry, and looked dark because of the multiple layers.
Shedding in strips is a strong indicator of humidity that is too low. I keep my corns on Aspen, so I give them a humid hide (using damp sphagnum moss inside of a hide, box, or Tupperware container) as soon as they go blue, and leave it until the shed is complete. This works really well and lets the snake decide how much time to spend in there. My corns especially need it in winter, when I maintain an ambient 77* viv room temp by turning up the electric heat.