Maybe a bug?

I am a lawful neutral character, and I do only good and neutral things. I had a 29th level sorcerer and I wished to improve him to max level (31), and I learned how to find Staff of Magi, so I played the game once more with him.
I was curious, so I killed Drizzt when I played the game second time (way back from Underdark Exit to Athkatla). I took his items.
When I killed Bodhi, his friend Harpell appeared, and wanted the items back. It is useless to say that "those are mine!" because he simply takes them.("the party has lost an item" 7x) So I cheated him: I put the items to the ground. He appeared again. I cheated him again. Finally, he appeared and cast Imprisonment on all party members, but I used Spell Immunity. Then I freed my friends using the Freedom spell.
Since that, this Harpell appears when I arrive to a new area or to a new district, and watches me, so my character turns into Harpell's direction all the time I walk in that area.
So very annoying...
This happens repeatedly if I get into a new area...
So he follows me everywhere
(exception: The Hell, the Abyss)

Did anybody meet this bug (?) ?
Maybe it is not a bug...

It always happens. Harpell will always appear time after time i you take Drizzt's items.

Drop all items but one. Whenever he demands the items, give him that one. He won't appear again and you get to keep all the rest.