So far in the patent infringement legal tussle between Sonos and Google, the former has notched several wins. But a ruling issued Friday has suddenly reversed that momentum, and Sonos has now been dealt a major setback. US District Judge William Alsup tossed out the company’s $32.5 million jury verdict win against Google and said two of Sonos’ key patents are unenforceable and invalid. That could make it much harder for Sonos to challenge other technology companies in court under similar claims of infringement.

“This was not a case of an inventor leading the industry to something new,” Alsup wrote in a decision that strongly criticized Sonos for bringing the suit in the first place. “This was a case of the industry leading with something new and, only then, an inventor coming out of the woodwork to say that he had come up with the idea first — wringing fresh claims to read on a competitor’s products from an ancient application.”

As Reuters reported on Monday, the reasoning boils down to this: according to the judge, Sonos wrongly linked a pair of patent applications in 2019 to a much earlier provisional application from 2006 in an attempt to claim “a priority date before Google’s disclosures and product releases” that would thus put Google under “a cloud of infringement.” Sonos is also said to have discreetly made amendments to the documents, which greatly frustrated the judge.

Above all else, Alsup says Sonos simply waited far too long to raise any concerns of patent infringement. Here’s the key paragraph from the decision on that:

The essence of this order is that the patents issued after an unreasonable, inexcusable, and prejudicial delay of over thirteen years by the patent holder, Sonos, Inc. Sonos filed the provisional application from which the patents in suit claim priority in 2006, but it did not file the applications for these patents and present the asserted claims for examination until 2019. By the time these patents issued in 2019 and 2020, the industry had already marched on and put the claimed invention into practice.

The entire ruling is a deep dive into Sonos’ history, multiroom “zones,” and other underpinnings of audio casting technology that Sonos and Google have now spent several years arguing over. In another part of the decision, Alsup digs into Sonos further:

Sonos has done exactly what the Supreme Court has long said should not be done. “It will not do for the patentee to wait until other inventors have produced new forms of improvement, and then, with the new light thus acquired, under pretence of inadvertence and mistake, apply for such an enlargement of his claim as to make it embrace these new forms.” 

Alsup, who has ruled on many of tech’s biggest court cases, warns that Sonos should avoid leaning on the earlier May verdict if it decides to pick a similar fight with other companies in the future. (Sonos has previously alleged that Amazon is also in violation of its patents but has said it only has the resources to take on one big tech competitor at a time.) “It would be a miscarriage of justice for Sonos to assert that this district judge has already found that written description was adequate when, with the benefit of the trial record, it has since become evident that it was inadequate.”

He saves his harshest criticism for the end of the ruling, where he closes with this:

It is wrong that our patent system was used in this way. With its constitutional underpinnings, this system is intended to promote and protect innovation. Here, by contrast, it was used to punish an innovator and to enrich a pretender by delay and sleight of hand. It has taken a full trial to learn this sad fact, but, at long last, a measure of justice is done. 

Ouch. Sonos says Alsup’s decision is “wrong on both the facts and law” and plans to appeal. Meanwhile, the company and Google continue to square off at the International Trade Commission and are entangled in several international lawsuits, with no sign of a settlement in sight.

The predicament continues to affect consumers, with Google Assistant absent from Sonos’ most recent products including the Era 100, Era 300, and Move 2. Sonos has said Google Assistant’s removal stems from back-end changes Google has made. “It’s a pretty heavy engineering lift for us to implement what they’d like any third party to implement,” CEO Patrick Spence told me in March.

We can only hope that Alsup’s stance on the case might bring Sonos and Google closer to hashing things out and finally settling this drawn-out rift.