Enderman stop being hostile after Knockback. No Teleport, No endermites.

Version 14w31a
Playing on Hard difficulty.
I'm using a Diamond sword: Sharpness 4, Knockback 2, Unbreaking 3, Looting 3.

Enderman behavior has changed (at least in The End). They often stop being hostile after being struck with Knockback. They never teleport away but just keep walking straight at you making them easy to kill, and never spawn endermites.