Originally Posted by Fat Zog
Yeah, I thought of that, but at the time it uses shadow claw there isn't actually another target. I'm pretty sure that trying to hit a non-existant partner doesn't work, too.
You are always allowed to select your partner's position, and any adjacent position really, with single-target attacks, even if there is no Pokemon at that position.
Go in a wild double battle with two Pokemon on hand and get one of your own Pokemon knocked out, then try to attack the empty space and see what happens.