[GAMEPLAY] Tahm and Gragas

I've noticed in Dominion playing Tahm, occasionally when I devour a large minion and spit it back out, instead of dying it will have 1% health and be invincible. It usually sits in lane and fights other minions for about 10-15 seconds before dying.

Just now playing Gragas in Aram, I threw out a barrel right as I was silenced, the barrel disappeared and I never could activate the explosion. For the rest of the match I couldn't use my Q and it gave me activation info. 0 mana cost 0 sec cool down. I tried relogging during the match and of course leveling the ability. Reassigning the hotkey/clicking. Nothing worked. But hey, we won.