Hmmm... it can work in reality, BUT .. then, the sick person you pickpocked his/her cure can't be healed at all !
So Stabbey is right: the cure potion must go away in the NPC's inventory after he/she drink it and heal him/herselves !
If I remeber : I give a cure potion and immediately the person is healed and your hero get XP-points for it.
So play it "nice", your hero get less XP.
