At what point does being bad become inting

I recently played a game with a maokai support that went 0/15/15. He was in a trio with the bot laner and the jungler, and they claimed that he was just really bad. I want to know at what point does being bad and dying an absolute crap load of times become inting.

Also its understandable that different roles have different standards so its not fair to just look at deaths, as its more (socially - solo q wise) acceptable to die as a support than it is as say a solo lane, or for a mid laner to trade kills and sometimes end up with a high number of deaths but also a high number of kills.

Now mind you i know that everyone has bad games and sometimes its hard to distinguish, but is there a line in the sand that you (riot) follows when it comes to deciding whether someone is inting or not? Because sometimes it feels like these kind of players, while they may say theyre "bad" just dont care about the game and dont care if they ruin the game for their team.

Im not trying to rant, or vent frustration or anything just curious as to how it is judged.