melkoriii said:
Still that quote does not account for Two weapon Fighting.
As Artoomis pointed out, this is only an issue if the monk attacks with the sling and an unarmed strike in the same full attack action round. If you can even do that.
melkoriii said:
This would be the same thing as having a Fighter useing a Bow take AoO with his Armor spikes.
I don't have a problem with that, as long as the fighter uses the hand which isn't holding the bow at the time (and so maybe getting an off-hand penalty). I can see that some DMs might consider the bow to be always requiring 2 hands, in which case they could reasonably disallow this; but I don't recall this being addressed one way or another in the rules.
I'd certainly have no problem with a hypothetical bow-using monk using an unarmed attack for an attack of opportunity, even in a round when they used the bow because they can use a kick to deliver the attack of opportunity.
Looking at your original post, I'm wondering if your concern is with whether a particular weapon is "ready" or not. In 3.5 there's no conception of "readiness" of weapons (shields, yes, but weapons, no). If a weapon is in hand and there are enough free hands to wield it (and is loaded, if that is required), it can be used.
If there's a problem with the original poster's description of the monk's attack actions, its that the monk didn't seem to take the move action required to reload the sling if they used the sling twice in a row.