Should a Mob be Able to Run so Far Away it Unleashes Itself and Forgets About You?

[loramin]

While doing the Tainted Aqua Goblin camp for my Druid's epic I dragged a couple of PHs to the island above the underwater tower. I DoTed them both below 20%, but then I had to deal with something IRL, and when I came back both their roots had broke and they'd ran off into the lake.

It's virtually impossible to cast or hit them in the water (which seems like a bug), so I just sat and waited for them to heal up enough to come back ... but they didn't.

Instead one completely unleashed himself from me, and went back to his spawn point (and full health). The other tried to do the same thing, but I was able to catch him just before he got back to the spawn point, so he still had low health.

On live I don't remember a fleeing mob ever just forgetting you and going back to its spawn point, so this seems like a bug. But, my memory of classic isn't perfect, and I have no evidence to file with the bug, so I thought I'd ask for some wisdom from the crowd on the topic.