Hey Lyte, you should add in a place where the Tribunal Voter must give his input about why he pardoned or punished, that way the voter must back up his/her choice and also can help you gather information about why people choose to pardon or punish certain cases.
Like for example, I just actually went on Tribunal right before posting this, and I had a guy who was reported on 5 different accounts for negative attitude. Sure, he had some temporary "toxicness" in his games, and generally had an upset attitude, but being an avid player myself, I saw that 4 out of 5 of the games, he had a team that had quit on him before the game even started. That would spark anyone's anger, and I felt for him. Even though he did in fact break the rules if you consider it in black and white terms, the guy was just having some bad games, and his reactions were only human.
So, I ended up pardoning him. If the Tribunal is all about putting away the players that bring down the game, and slap the wrists of the people willing to change, then you should definitely allow the voter to give his input on the subject. I for one have a temper in some games, and it has led me to my first warning. If you created some sort of thing that transfers these people's responses anonymously, I feel that it would help a lot. If I could have just sent an anonymous message to that guy, saying that if he keeps up his attitude he's going to get in trouble, and that he should just take a break for a while and do something else when he's pissed off, it will help him a ton. I know when I get carried away, I'll continue playing and just continue getting more and more mad. But if there was a message from someone who pardoned or punished me saying that I just need to relax more, I really doubt I'll do anything but relax.
One more idea is to add the player's summoner level. When I see an ashe with 0/10 revive ignite, I tend to instantly assume troll, but reading through the text made me come to the understanding the Ashe was just new and got annihilated by the enemy. If people didn't put a lot of thought into it, they would just insta-punish someone like this.
Just my point of view, hope I sparked some ideas in you. (: