Check all the chat logs when reviewing a report
I was once banned I was in an argument and the guy reported me I didn't figure much but I got banned I doubt that the other person received any punishment. I want to get to the point when reviewing a report though it can be more time consuming please check the chat logs from every one that or either the one who reported the other as they can antagonize the other player, flame the other player, or int the other players lane. Many of the bans given are likely to be misunderstood as why that situation occurred in the first place. From my experiences any flaming or arguments have a good chance of someone starting the situation and then playing the victim saying they're going to report. Sometimes people simply forget to report in the end game lobby and therefore they can get banned and the other person who deserved the ban just as much gets away scott free.
Edit: for those who misunderstood I am saying both players should receive a ban not one get away free because the other started the argument.