Winning vs. S (is this griefing?) (unsure if this should be in player behavior, but also gameplay)

So, let's say you are pretty certain that by picking a farming jg, you can aft farm at 7-10 cs per min and probably pick up a couple kills and assists along the way without risking a death. Without risking death or losing cs, unless the other team sucks, you're going to lose a lot of 5 v 4 drags and towers and such. So my question is, lets say i want a lvl 7 mastery token and want to afk farm my way to the token, would this be reportable?

TO BE CLEAR: I am not talking about playing passive and team flaming you for not carrying them. I am talking about something like this: its about 10 mins, I am elise with 75 cs, full health/mana, and maybe i took a kill that was free (my mid alkali ignited enemy veigar who had 10 health, so i stole kill) and the enemy team is all under 10% at infernal drake. 3 of my teammates at full health, probably even in gold with enemy, are closing in on drag, but I do wraiths instead of helping fight. Enemy team takes drag, 2 teammates die; 3 enemies die. Had I helped, there is a chance i would be focused and die, risking my S, but more than likely we take the drag and nobody else dies on our team. Clearly, the team is hurt by this decision, but who cares if its a norm game and I want a token?

Asking for a friend.