That's a pretty good (and pretty much my own) policy, really.
Ever since the Palutena statue and the leaked model were incredibly, incredibly similar, I found it really hard to not believe it.
There is plenty pointing towards it being real honestly.
1) unique Palutena and Mario models, neither with an original source or origin
2) unique backgrounds
3) In my opinion, the clipping of Palutena's hand should lend more credibility, showing that it's an actual 3D model rather than a ripped picture or something.
4) scans have been run on said picture, which haven't picked up any sort or disturbances such as ones that would be left by Photoshop
5) the outlines and parts of the pictures are consistent with many different 3DS pictures that have been on the official website.
6) there are two pictures, not just one
It would have taken a crap ton of effort from the leaker or creator of the images to make these picture from scratch, and they would have to have access to pictures we've never seen before (as far as the backgrounds and such). To me, while the effort could have been made, I do not see why somebody would be putting that sort of effort into Palutena, nor have I ever seen such a well done leak in my life.
If you ask me, it's real.
The only thing people bring up to say it's fake is, "It's fake because I don't believe leaks"