Mobs will not stop running after being hit.

I noticed when hitting a cow to get out of my paddock, that the cow did NOT
stop running. Usually mobs would stop running after being slapped by the player though this cow was unable to stop sprinting in circles. Just my MAC having a mess or a bug?

To reproduce:
Go on a world that you are willing to mess up the animals in and spank a cow on the bootie and you will see it runs and runs and runs and runs and runs and runs and runs and runs..........