reverse the 1-2% hps left after a sure death hit...

Vallter: I assure you that no such changes were performed. And I, as a player as well, can understand the pain, when sometimes enemy gets away with 1-5% lefts. But this is not something done specificly.
Side note, on EU I have seen the thread with player stating that guns deals more damage specificly to kill him and not leave with 1-5% -)