Mob running/move too fast after hit

Sometime the mob running/move too fast

^{Addition by [Mojang] Mega_Spud (Jay Wells)}
It seems that mobs generated before the latest update (0.15.90.7) are affected by this, and will move at a much higher speed than normal.

Update by [Mojang] Adrian Östergård
This bug has been reported to our internal bug tracker for further testing and a fix. It is scheduled to be fixed in one of the future updates (no specific date can be provided).
Please avoid duplicate comments. Post only NEW information regarding this bug.