Last month, I bemoaned in this column how the Wal-Mart employment litigation makes our legal system look bad. For more than a decade, the women who have charged the retailer with sex discrimination in hiring and promotions have been left in legal limbo, waiting for someone to rule on the merits of their claims. The case marks the height of judicial inefficiency.

So I was heartened to read an opinion that not only sang the praises of economy and efficiency in civil litigation, but actually put those sentiments into action. In a case alleging that Whirlpool’s high-efficiency washing machines are prone to developing smelly mold, Judge Richard Posner of the U.S. Court of Appeals for the Seventh Circuit on Tuesday issued this bracingly concise eight-page opinion [PDF], reversing a lower court and holding that consumers could bring a class action. (You can read our previous coverage here.)

The lawyers for defendant Sears, Roebuck and Co., which sold the Whirlpool machines, tried their best to frame this case as a highly complex matter that defied class action treatment. They pointed out that Sears sold 27 different models of these machines since 2001, when the class period started, so class members owned different versions of the washer. And the majority of purchasers, they argued, hadn’t complained about a mold problem. As a result,they argued, the class couldn’t be certified under the Supreme Court’s Wal-Mart standard because common questions of fact about the mold don’t predominate over individual questions. The district court accepted this argument and denied class certification.

In reversing, Posner made a statement that’s almost breathtaking in its simplicity and good sense. “Predominance is a question of efficiency,” he said. “Is it more efficient, in terms both of economy of judicial resources and of the expense of litigation to the parties, to decide some issues on a class basis or all issues in separate trials?”

That shouldn’t be a shocking statement, but it is. In the wake of Wal-Mart v. Dukes, in which the Supreme Court majority appeared unconcerned about efficiency, Posner’s pronouncement seems almost radical.

I wouldn’t be surprised if the Supreme Court took up this case, or a similar case from the U.S. Court of Appeals for the Sixth Circuit. There the court upheld the certification of a class of purchasers suing Whirlpool (as opposed to Sears) over these washing machines. Whirlpool, represented by Stephen Shapiro of Mayer Brown, has petitioned for certiori [PDF], and the court has asked for a response brief from the plaintiffs.

The Sixth Circuit’s ruling has alarmed the business community, where many had hoped that Wal-Mart would eliminate pesky cases like these. “The future of all manufacturing in the United States hangs in the balance [of this case],” cried Tiger Joyce, the president of the American Tort Reform Association, in an op-ed piece last week in The Washington Times. Joyce urged the high court to “nip in the bud” the Sixth Circuit’s kind of thinking.

Posner is a very smart judge. He’s thought through the consequences of certifying this class, and he sketched out in his ruling how this class action might proceed, based on individuals’ varying claims. I fear his simplicity might annoy Justice Antonin Scalia, who wrote the Wal-Mart opinion, and the others in the majority. You could come up with complicated reasons why this class action wouldn’t work. But sometimes the best answer is the simplest.

This article originally appeared in The AmLaw Ligitation Daily.