Oh, the AoO is a critical. Well if needed here is confirmation and extra damage:
Attack:
Rolled 1d20+3 : 7 + 3, total 10
Damage:
Rolled 4d4+8 : 4, 2, 4, 4 + 8, total 22
I didn't specify a target with my primary attack, but I'd think my primary target would be the big frog, and my secondary target would be the smaller frog. The AoO hits whoever makes the first move of the frogs.
EDIT: Argh too many edits, anyway those were my rolls.