Turret losing armor

Since the last patch, I think that I noticed a bug concerning the rework turrets on Summoner's Rift.

Turret resistances BASE ARMOR AND MAGIC RESIST 100 ⇒ 0 NEWWE CAN REBUILD Turrets gain 2 armor and magic resist per minute, up to a maximum of 30. Outer towers begin scaling at game-start, Inner towers at 15 minutes, Inhibitor & Nexus towers at 30 minutes. REINFORCED ARMOR Turrets gain 300 ⇒ 200 armor and magic resist if no minions are nearby

I noticed that the turrets armor drop to 0 when you hit the turret wich result in minions/champions do deal true damage to turrets.

This results in team able to snowball gold lead pretty fast since turrets dies too fast.

Here a link to one of my game as Tryndamere.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2008433006/209851989?tab=overview

I took the outer Top lane turret at 10:14 and the inner Top lane turret at 11:03 with only Guinsoo's Rageblade as a complete item while being able to force my lane opponent out of the lane between the turrets.

So it took me 49 seconds to force my lane opponents out of lane and taking his inner turret before 12 minutes into the game since turrets have no armor.

So thank you for reading this.

Krazull