Unstable Gas is a permanent.
If you are arguing mechanically, that TU should make it on the opponents side of the field, then im sorry, but you are just plain wrong. Normally anything you say QT, I pay close attention to and considerer well thought out, however, mechanically, it would be BACKWARDS for it to put it on the opponents side of the field because no matter how you look at it, YOU are casting the spell, not the opponent.
Now if you are arguing balance wise that it should be put on the opponents side of the field, that is another thing entirely, and you should instead discuss that on the link you mentioned that this card has on the nerf this card board. Game Suggestions general, when it comes to cards, should only deal with mechanics, and not balance.
So in summary, balance wise, I make no comment on what Pandemonium should do with TU, however, mechanics wise, it is doing exactly what it should do.
Ninjad by RC