I know this makes me look like I'm really on a crusade against Shino, but I just want to check. How does him randomly killing two badguys because you changed his target prove he is good? You could argue that on the days he has used it himself, all he has done is kill good / neutral guys, and has only killed badguys when misdirected.
Also yes, I realise thats most likely a coincidence, but still. I don't think it "proves" he is good.