If i shoot somebody and he dies in the some moment, obviously my skill don't hurt him, but It also don't give me charge points, but if somebody shoots me when I use shadow sleep, it hits me (unless the attack miss, but that makes me go into battle and makes me so vulnerable). In mutated condemned mine I died a lot of times because when I use that skill, in that moment a mob start casting its magic skill and with that the mobs stands in battle untill it throw the attack, which makes me seeable (if it doesn't kill me) and all mobs start to hit me again.
In my opinion, when I use shadow sleep, the effect should be like if I die, every attack that anyone starts to charge against us, should be canceled, and if they have already launched the attack, it wouldn't make effect.
My point is, invisibility can be a tool for a ranger, but for us it's a big limitation. A ranger without hide lose something, but not much. An assassin without hide, almost isn't an assassin we lose our only area attack and our best skill (shadow demon strike), so shadow sleep shouldn't be so easy to lose.