Anduin: Lightbomb - Push Forward bug

Anduin doesn’t receive stacks for Push Forward from enemy hereos hit by Lightbomb, whether cast on self or an allied hero.
Reproduction:

  1. Enter a (optionally sandbox) game as Anduin.
  2. Get at least level 13, picking Lightbomb at 10 and Push Forward at 13.
  3. Cast Lightbomb on either yourself or an ally hero, making sure to hit at least 1 enemy hero in the explosion.
  4. Note that the stack counter of Push Forward hasn’t increased through this damage.

Expected behaviour: As Lightbomb’s explosion results in Anduin dealing damage, this would be expected to yield Push Forward stacks when it hits enemy heroes like any other source of damage.