[GAMEPLAY] [BUG] Enemy Bard Ults Tower Making it Destructible

The bug is when, Bard ults on his tower it becomes destructible, on the picture you can see the bot Inhib tower is down and one of the inner bot towers are still there. I didn't realize the bug till we noticed the super minions breaking the inner turret in bot lane.

1. Enemy Bard uses R on his tower and himself. (There has to be another tower in lane like in the picture)
2. The tower that ulted on becomes destructible after that.

Video

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1759410354/207137390?tab=overview If you look at the building kills and check out the bottom towers you can see that Inhib tower was broken before the inner tower.