That is a very amature way of analyzing a trade. So many people think there is a clear "winner" and "loser" to a trade, which is, again, very amature. Without knowing each teams trades, we cannot acurately determine who gets the better end. The motive for a trade can lay much farther beyond the players involved in the trade.
At this point, with Hiller's injury, if you are saying that he is still better than Ellis by a "country mile", you clearly are not looking deep enough. Take a look at Hiller's injury, and his injury history, along with his contract, the Ducks cap dilemma, and you will see that there is at least a reason to argue that Hiller may be moved in the offseason, or at the very least, may miss considerable time for the remainder of the season. Taking further into account is the fact that his injury is so dizarre, and may be reason for concern going forward.