If not as intended, i would say as should have been.
It is logical, hostile mob walking back, sees you standing there, you are a valid target, so hostile mob pounds you in the head.
Before WOW launched in 2004, i had been playing EverQuest
and it was a normal thing, mobs never gave up until you died, or zoned out (in EQ you did not seemlessly walked between zones)
and anyone in their path when they lost their target was fair game.