Don't stress too much about the mis-step, all is forgiven.
In terms of the method of holding the shuriken, it's a not brilliantly done form of the Meifu Shinkage Ryu method, a modern method currently in it's second generation, with the founder learning Katori Shinto Ryu from Sugino Yoshio. She's missing all the Reiho (a core component of the system and it's methods), and getting her positioning wrong.
For reference, here is the current head of the Meifu Shinkage Ryu, Otsuka Soke:
Note that the initial position is held further forward, nearer the temple than the ear, the throw is performed as a "whole body" action, the shuriken is situated a little higher in the hand, there is a "snap" to the throw, and more.
Oh, and in terms of the video itself, unlike someone like John, I'm far from sold. It's basically a disguised ad for a website (a slip or two near the end are dead giveaways, and remove speculation), rather than an actual review, and that leaves a bad taste in my mind for such things. There is a very good source for such things (far more along the traditional lines) if you're interested, but I'll let you know that in person.
