[JJ]

Was your first thought "He offered at the pitch"? That should be your first decision. If he DID, it's a strike and the ball's dead (because it hit him). If that was your first thought and you weren't sure, that's when you go to your partner for his thoughts ("Did he go"?).
If you don't think he offered at the pitch, then you have to decide if he initiated contact with the ball - would it have hit him if he hadn't moved, or, did he move into the pitch to get hit deliberately? If he is guilty of that, then the pitch is a ball and he stays up to bat.
If he did not try to get hit, and IS hit, and he didn't offer at the pitch, award him first base.

Your post is a bit unclear - what DID you rule? Strike? Ball? HBP?

JJ