Having played with the PC this issue relates to, I love the build. However, I see the problems it can cause.
There is a precedent on the FAQ indicating a single action may provoke more than one AoO . ie casting a spell that results in a ranged attack (Scorching Ray). Casting the spell provokes and making the ranged attack provokes. However, if the spell results in multiple attacks, only one AoO is provoked for the attack event because they are fired "simultaneously".
Carrying this logic a bit further: If you consider each attack within a full round action to be a separate event that provokes the Bodyguard feat, the GM could calculate how the attacks are occurring. For example, if your opponent attacks twice because of a two weapon fighting attack the GM could legitimately rule that the attacks are simultaneous and only one could provoke the AoO per the FAQ. A claw, claw and bite attack could similarly be ruled as simultaneous and thus only provoke a Bodyguard AoO once.
You could also have a GM interpret this same FAQ as indicating all attacks within a full round action are a single "event". ie spell casting is one event and attacking is one event, etc... A further clarification from Paizo on use of what constitutes an "event" within an Action Type would help. Without it, I could understand PFS GM's calling each attack within an action an event or all attacks within an action a single event. You should be prepared to sit with GMS's calling this either way. I think I lean towards the simultaneous option at the moment.
Overall, this does not initially seem like a big deal until the Bodyguard is a Halfling granting a +4 instead of +2 and stacked with other Aid Another buffing magic items cranking the allies AC bonus another 2 to 6 for a total of +6 to +10 just for hitting an AC 10 on an AoO. At some point, this build begins to poke the GM with a short stick. Part of the fun of this game can be to find some of the outrageous combos and see them play out. I just caution about doing anything at the game table that causes anyone else (even the GM) to feel they should not have bothered showing up.
That said, I am still curious to see what the ultimate AC of someone standing between your Bodyguard and my Shielding Fighter will be during our next game. :)
