I don't understand it

Canadian Press reports that the Harper government is going to stomp on the outstanding legal cases of the lumber companies who reject the softwood lumber deal.
And here's what I need somebody to explain.
The story reports:

The court earlier struck down the U.S. lumber industry's claim Canadian imports posed a threat of injury and was set to rule on whether the roughly US$5.3 billion in duties collected since May 2002 should be returned.

Why is the Harper government so damned eager to abandon the court cases which may well declare that ALL of the US duties are illegal? Wouldn't our bargaining position be stronger if we won this case?