Flint and Steel on Husk

I spawned a lot of husks, and set fire to one with a flint and steel. It caused the world I was playing to go very buggy, and the other worlds I tried were also like that afterwards. All that was in the superflat world was a pixel art made of slime blocks and wool (in differemt colours), and the other world was a default world with nothing built in it. Pictures attached.