[GAMEPLAY] Carrying minions with Ryze Ult causes them to attack untargetable turrets if in range

So I decided to do a custom game to try out the new Ryze, and while messing around I noticed that when I teleported my minions from the turret they were attacking to the next turret, they would attack it even though it was untargetable.

I was able to replicate this bug with 100% success on regular turrets, however Inhibitors, Nexus turrets, and the Nexus Obelisk were not targeted by the minions.

I don't know how many screenshots I can upload at a time, so I uploaded all of the screenshots I took on Imgur. Here's a link

Here is the surefire way of replicating the bug:

1. Start a custom game as Ryze.
2. Go into lane and farm minions until level 11 (I couldn't get the bug to work at level six, as the range was not long enough for the minions to target the turret.)
3. Gather a large group of minions near a turret (preferably the middle turret)
4. Cast your ultimate right beside the next turret in lane and make sure that your minions are in the portal
5. ???
6. Profit.