I enjoyed this encounter so much I decided to look at every outcome. Anyway, If you choose and succeed on your dialog rolls you can fight just BOOOAAL. After killing him and looting his nice sickle (the normal one) you can talk to the Kuo-Toa Priest and he gives you options to choose, the only problem is you are locked into dialog with him. When you try and select an option it shows your name next to the option, but nothing is choosen. There is no way to back out of this dialog. If you change party members they can run around, but the main character is locked in dialog. Clearly this breaks the quest and the game.
Another slight bug with this quest, if you choose to be the champion of BOOOAAL, his magic sickle he gives is incorrect. It only does 1d4 as opposed to 2d4 the other 4 do.
All hail MAHKLOOMPAH!