Here is the link to a video I recorded of the bug I encountered:
I already know the battle was lost since the Ice Cubes from evil against whom I was fighting would heal out of my reach, but I noticed a bug while playing with Ragnaros with the Sulfuras Equipment tier two. That should not have happened, as they prevented me from attacking them over and over again.
I hope the Hearthstone team can look into it! Until then and after then, have a nice time in the Tavern!