Chermorg has a very good point here. Rather than telling us on the forums, and being upset that Riot isn't doing anything, submit the proof to Riot in a support ticket. You've got a screenshot, and with the new replay functions in the client, it's easier than ever to get more of them. Unfortunately, you need to rely on the in-client report system for the chat logs of where he/she said those things, but if they did any specific trolling actions, then you can submit those pictures as additional information. And it only takes about as much time to submit a ticket as it does to make a post here on the boards.
In some instances, with very farm intensive junglers who have extremely weak pre-6 ganks, you may end up with a low total damage to champions... if the game happens to end very, very quickly. But with a champion like Kindred, who is dependent on champion kills for a significant portion of her passive stacks, it's easily a form of griefing to have no damage dealt to champions. I'm not certain if she has to get the kill, or if an assist will stack her passive, as I don't play her and have only looked at her once since they updated her passive, but either way, she would have to be dealing damage to be actively engaging in playing her champion correctly. And if she isn't playing the champion correctly and trying to actually win the match, then he/she is griefing the team, but without you submitting the report and extra documentation, it can be hard for Riot to simply "know" everything that happened. They are going to give the players the benefit of the doubt; maybe Kindred was just a very ignorant player, and not actively trolling, and we don't want to punish someone for playing badly, only for being a bad sport. Think of it this way, if you happened to have a bad match. Say you were camped by the enemy team, you had ping issues, or any number of other things going on, but you ended up dying ALOT. Would you want Riot to automatically ban you because someone on your team said you were inting? Or would you want them to at least investigate the situation, and give you the benefit of the doubt?