This is one of those "ripped from the headlines" strips - as devastating as that might seem. He'd never actually cast the spell before, and it works differently than he thought. By default, it puts one of the portals by you - so where you target the spell is actually the other end.
There is a powerful redemption arc, though. The very next game he served as a kind of quantum valet for the party, delivering us with his sorcerous skills directly to the exit, key in hand. But the first time, when I saw the two portals, like… adjacent, I thought maybe there was something fundamental about the game or perhaps even reality itself I didn't fully comprehend.