A judge has overturned a $32.5 million judgment against Google in the tech giant’s long-running case against Sonos over smart speaker patents.

In an Oct. 6 decision, U.S. District Court Judge William Alsup ruled that the jury verdict from May that found Google had infringed one of Sonos’ smart speaker patents was invalid because the patents at issue in the case were “unenforceable.”

In a nutshell, Alsup claims that Sonos improperly linked its 2019 patent application, which was ultimately approved, with an earlier, rejected 2006 application for the same patents in an effort to show that its patents pre-dated Google’s products incorporating similar multi-room audio technology. The judge alleges the link is invalid because Sonos “deceptively” inserted new material into the 2019 application without alerting the patent examiner of the changes. He notes that when a continuation application for a patent — as was the case with the 2019 application, which was filed as a “continuation” of the one filed in 2006 — includes material not included in the original application, the two cannot rightly be connected.

“When new matter is added to a specification of a continuation application by way of amendment, the effective filing date should be the date of the amendment that added the new matter,” Alsup wrote. This effectively means that Sonos’ “priority date” for the patent would be Aug. 2019, when the amended application was approved — not 2006.

Alsup additionally accuses Sonos of “an unreasonable, inexcusable, and prejudicial delay” in filing suit against Google. He states that in 2014, five years prior to Sonos’ 2019 patent application, Google had shared with Sonos “a plan for a product that would practice what would become [Sonos’] claimed invention” as part of an exploration of a potential collaboration. When that partnership failed to come to fruition, Alsup adds, Google began rolling out its own products that utilized the invention in 2015.

“Even so, Sonos waited until 2019 to pursue claims on the invention (and until 2020 to roll out the invention in its own product line),” he writes.

“This was not a case of an inventor leading the industry to something new,” Alsup continues. “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.”

“Judge Alsup’s ruling invalidating the jury’s verdict is wrong on both the facts and law, and Sonos will appeal,” a Sonos spokesperson told Billboard in a statement. “The same is true of earlier rulings narrowing our case. While an unfortunate result, it does not change the fact that Google is a serial infringer of our patent portfolio, as the International Trade Commission has already ruled with respect to five other patents. In the end, we expect this to be a temporary setback in our efforts to hold Google financially accountable for misappropriating Sonos’s patented inventions.”

Google did not respond to a request for comment at publishing time.

Sonos first sued Google in January 2020, claiming the tech giant had infringed multiple patents for its smart speaker technology after gaining access to it through a 2013 partnership under which Sonos integrated Google Play Music into its products. Just two years after that partnership was reached, Sonos alleged that Google then “flooded the market” with cheaper competing products (under the now-defunct Chromecast Audio line) that willfully infringed its patented multi-room technology. Sonos additionally claimed that Google had since expanded its use of Sonos technology in more than a dozen other products, including the Google Home, Nest and Pixel lines.

The legal battle between the two tech companies has been protracted, with both sides going on the offensive at different points. In June 2020, Google filed suit against Sonos, alleging the smart speaker maker had actually infringed several of its own patents. Sonos subsequently filed two more lawsuits alleging that Google had infringed several additional patents it held.

Sonos filed one of those two cases with the U.S. International Trade Commission, which ruled in January 2022 that Google had infringed a total of five of Sonos’ audio technology patents and barred it from importing the infringing products from China. However, the commission also found that Google had successfully redesigned its products to avoid the Sonos patents and could continue selling those reworked versions in U.S. stores — an allowance Sonos had fought to prevent.

In August 2022, Google fired another volley with two additional lawsuits, claiming the smaller company used seven different patented Google technologies to instill the so-called “magic” in Sonos software.