T.N.T and Jotun

I just came across a really weird interaction, I was going against a Shaman who Azerite Murloced into a Jotun (DH Legendary that casts the first spell draw each turn). When my opponent would start their turn by drawing a T.N.T, Jotun would cast it, but it would destroy stuff on MY side, I have no idea how this happens but I wanted to document it here so people may know and hopefully it gets fixed