Creatures that damage the player or planeswalker they attack are also dealing damage when attacking a Battle

Myr Battlesphere's trigger says it deals damage to the "Player or Planeswalker it is attacking". A Battle is not a player or planeswalker, so no damage should be dealt, according to the MTGJudge chat. I'm not aware of an official ruling on this, and would not be surprised to see it eventually eratta'd - but for now I believe the XMage implementation to be incorrect.