BM'ing: Is there a line?

Alright, well. I just played a game where we obviously weren't doing so hot but not once did I put a surrender vote up; the game lasted 35 minutes. The team I was on were fairly decent, and mind you this is just a normal, not a ranked. The support on my team, started to flame me and usually I just ignore them or mute them. But, I just thought he would say one thing and be done with it. Clearly, he wasn't done and said, ''...Go ahead, report me you %%%got.'' and, personally I do take offense to the word, so i did sort of feel hurt. I just left it alone though and tried to keep jungling, getting my CS up to buy some items so I could help my team; we were so far behind by this point. The support and mid-laner kept pinging me, so I said ''What?'' and they wanted me to come help. So I finished my camp and came and I guess I was 'too late' and the support got extremely pissed. He said, and i quote, '' Kill yourself fucking %%%got.''

Now, I get that it's just an online game and you shouldn't take the things people say too personal, but to me that's where the line is drawn. Personally, I think telling someone to kill themselves, regardless of it being a joke or what-not, is a low blow and just pathetic. So, I'm asking; do you think there's a fine line between bm'ing and, I suppose you would say, cyber-bullying? I know it's not particularly a big deal to most people, but I just want to see where other people are coming from. This is just on my smurf account, so I to try not to say anything back to fight fire with fire. Sorry for this being, what I think, long. It just irks me a lot honestly and I feel like RITO does barely anything to the people who deserve their account banned. I just strongly believe, regardless if it's online or not, that telling someone to kill themselves is just wrong.

Thank you