Tripping grapplers

[RangerWickett]

How does tripping and grappling interact? If I'm grappling with an Orc, and the Orc's Goblin buddy trips me, I imagine I just go down, with no penalty to the Orc. However, if I've pinned the Orc, and the Goblin trips me, would both and the Orc be tripped? Or would I fall and the Orc would be unpinned?

Any ruling on this?

 

[Caliban]

Nothing official. The grapple rules don't seem to care if you are prone or not.