Ah, I wasn't expecting that. So, 4/5. However I DID have a feeling that Obito could see what Kakashi sees from the Sharingan.
So here's whats up:
1) We still have no real idea WHO Rin is. For all we know, Rin could be a spy that gave their location up to the Mist nins.
2) Why would they be even in the Mist at this time? Unless I am a bit foggy on the history. (puns)
3) People have said it's an accident because Kakashi isn't good with it yet. Maybe, but if it's been months since the Bridge and Kakashi IS a genius... There is a good chance he had almost total control over it.
4) The theory that he can't see well enough in the fog and hit her. This can be very true because when he was fighting Zabuza he couldn't see. BUT, I'm sure Kakashi told he to stay close so he can protect her.
5) Durring the Chunin exams the Mist nins could use a type of genjutsu (I think.. it was long ago). And even with the Sharingan, Kakashi can't quite break it, right? Could be very true... BUT if Rin is the Sakura of the group she must know how to release it as seen at the final round of the Chunin exams when Kabuto used a genjutsu.
6) Some say it's Madara's doing. We have no reason to say it isn't.. or is for that matter. We are forgetting a few things with him. 1) He's weak and old AND 2) He has his goonies that collect info from all over that knew about this... So unless you people can PROVE and I mean PROVE with solid SOLID info that he has something to do with it.. I'll be glad to read it.
I am going with my FIRST point.. her being a spy. Since that is the most likely considering Note 3 and point 1.
*Note: Obito grabbed the left side of his face and said "stop imagining things". He saw what Kakashi saw at that time.
**Note: If Obito is like Naruto he would have screamed and kicked his way to confront Kakashi.. So unless "Tobi" knocked his ass out????
***Note: Kakashi was crying, so either the genjutsu was released right on impact, or he knew what he was doing.