Summoner's Rift Tower Bug

Was recently playing a game, and I first noticed that the top tower hadn't been taken. When I got there I tried to auto attack it, nothing happened, as you can see in the screenshot, the tower said it had full hp. But the tower was technically destroyed, so the other towers in the same and other lanes went down fine.

I assume this bug occurred once the tower was destroyed, I should've saw the particles etc. when it was destroyed to see of anything weird happened. Anyone else seen this bug?