Something I never liked with the AoO rules is that they say that if you do something unsafe, you provoke an AoO.
Hop, you drink a potion, and bam!, an AoO appears from nowhere and hit you.
You don't provoke an AoO, you open yourself to letting other do an AoO on you.
But for them to do so, they have to be threatening you. You must be within one square they threaten, and they need to be armed (or considered such).
The only way you can do an unarmed AoO that "provokes" another AoO is if you're wearing a light or one-armed weapon in one of your hand (so as to be armed), decide to attack with your off-hand unarmed attack, and do not possess the Improved Unarmed Strike feat or class feature.