Well, Nico Robin did get involved.... but that was her choice.

Honestly I'm not sure if she's just trying to make us both uneasy or if she's actually plotting something. Which of course... is an uneasy concern. She's diabolical. [Spoken with a bit too much admiration.]

But we avoid getting anyone stuck in the middle who doesn't want to be. Hmm... I wonder if I could turn Sabo to my side...