[Gameplay] Possible Yorick ghouls/turret bug

Yorick ghouls draw turret aggro after some lane minions.

I know champion related minions usually draw turret aggro before any other unit (Tibbers, Zyra plants, Heimer turrets...). However I saw today during a stream that a turret didn't seem to attack Yorick ghouls if there were lane minions (it wasn't a case of the ghouls dying before the turret killed its curret target, it killed a minion and targeted another minion while ghoul was under it, and happened many times). I own yorick so I decided to try it myself and I discovered that the aggro order was:

Siege minions > Melee minions > Yorick ghouls > Caster minions

I don't think this is intended, so I decided to report it here. Is it?