[GAMEPLAY] Yorick pulls tower agro

while playing Yorick, if you place Dark Procession (W ability) on an enemy champion under their tower and the enemy is trapped in it, tower will switch is aggro to Yorick if he is within range of the tower even though the ability does no damage.

1. have enemy champion under their tower
2. have minions take agro from tower
3. place Dark Procession on enemy champion while within tower range
4. tower agro switches to Yorick even though no damage was dealt to enemy champion.

This has occurred in several games as Yorick (and against a Yorick) but not sure if it is intentional or not as other displacements do not pull turret agro.