Really weird Heimer turret bug

I'm not sure what caused this nor have I been able to replicate it since, but at one point in a game yesterday, one of the enemy Heimer's turrets remained active after he walked away from it (there was another turret that had deactivated not too far from it and was closer to the direction Heimer was) and was completely unkillable for a short time (at least 3 of us were trying to kill it). I tried to eat it twice (I was Tahm Kench) and I was able to move it slightly but it forced me to drop it immediately beneath me as if I had never actually ate it at all and my devour still went on cooldown both times. I didn't have vision of heimer at the time, but I think it only disappeared because he put down another turret elsewhere (other one disappeared slightly after). Only reason I thought this was worth mentioning was because our minion wave got stuck on it and couldn't push. If Heimer had realized that he probably could have exploited that against us.