The fireball hit for 26. Every person in the web that also got fireballed took 8 from the buring web.
OK, so the Fireball is by far and away the most dangerous thing that happened. It killed two party members (assuming the dog counts as a member.)
People who made their saves took 21; thats the Bard. The Centaur must have made his save, then taken 5 from the Monk since he lost 26 of 32. (I thought the Centaur went down? Did he get a potion? Is 26 of 32 correct?)
I guess the Mnk/Ftr did not get hit by the Fireball. He took d6 from the Pit assuming he used Tumble and Slow Fall. The rest of the 45 damage is due to the enemy Monk. Is this correct?
So the Monk did 45+5-d6 or just less than 50 points in the fight? Thats not too bad. Not as good as the Fireball, but not too bad either.