Ender Dragon head crashes game in survival 15w33c

So basically I was showing a friend the new dungeon and I went over to the flying ship and I broke the stair right behind the dragon head so I can collect the Dragon Head and when I broke the Dragon Head and it shot out a ton of soul sand particles and then I crashed. This was done in survival mode.
(It's 5 am where I am sorry if my grammar is terrible.)
Crash report below.