As a monk, if I cast paralysis on a mob from some distance away, I won't enter combat. If I then walk nearer to that Paralyzed mob, it puts me into combat.
As a DH, if I cast imprison on a mob from some distance away, I won't enter combat. If I then walk nearer to that Imprisoned mob, I still stay out of combat.
From a design standpoint, what is the reason for this difference in behaviour?