Tahm Kench and Heimerdinger Devour bug

I don't actually have any footage of this because I ain't got one of them fancy shmancy screen recorders, but still. I was in a game as and I kept trying to save my allied with Devour, but I couldn't use it on him. Now, this post might be a little premature since I don't know the interaction with enemy Heimerdingers, which could be just fine, or this could be a fluke alltogether, but in that game I couldn't Devour him which had him die 3 more times than he needed to. I haven't had any issue with the ability on any other champ, friend or foe. I'm not sure if this has been reported or not, because I can't navigate these boards to save my life, but I'll post this anyways.

Anyway, to try and see for yourself if this is the case or not, then just go into a game with an allied Heimerdinger and try to use Devour on him.