[SAump]

1) The runner committing interference is usually out, ball is immediately dead.
2) Interference rule suggests when the umpire cannot rule upon a play, here no throw to 2B - no play at 2B, the player closest to home can be ruled out.
3) By merely attempting to dislodge the ball at HP, we have an incidental malicious type of contact which may supersede obstruction.

I prefer ruling 7.06a obstuction only because the following interference ruling stinks, but it is what it is, as someone here would say.