AoO question

[humble minion]

Situation: a monster with reach (half-fiend shambling mound in this case) attempts to disarm a PC - who doesn't have reach - from 10ft away, using natural attacks.

Making disarm attempts provokes attacks of opportunity.

According to the RAW, the PC only threatens the squares in which he can make a melee attack, so am I correct in thinking that he cannot make an AoO at the mound since it is out of his reach? It seems a bit harsh on the PC to say "no, even though it's trying its best to wrap its tentacles around your weapon, your weapon isn't long enough to attack it."

Has this been clarified anywhere? Any decent compromises, or should I just go with the rules as written? Have to admit, I'd kinda like to (cos otherwise the PC WILL hit the mound's rather poor AC with his AoO and the disarm attempt will be wasted), but I do feel ever-so-slightly compelled to be fair...

 

[Vegepygmy]

According to the RAW, the PC only threatens the squares in which he can make a melee attack, so am I correct in thinking that he cannot make an AoO at the mound since it is out of his reach?

You are correct.

It seems a bit harsh on the PC to say "no, even though it's trying its best to wrap its tentacles around your weapon, your weapon isn't long enough to attack it."

Has this been clarified anywhere? Any decent compromises, or should I just go with the rules as written?

It has been clarified, in the FAQ I believe. It has also been suggested that if the DM finds that too harsh, he could allow the defender to make an AoO on the creature with reach, as long as it is attacking with natural weapons (i.e., attack the tentacle).