People get too mad over kill stealing if he was not getting pentakill.
On my terms KS means kill secured (unless ally is getting pentakill then I let him have it) while on the other hand some person in a BOT match flamed me for KSing and banking his lane when he was somehow loosing to beginner bots... How interesting. (I was helping my friend learn the mechanics of the game once he reached level 3 and could be invited and give her tips.)