In a potentially stunning development, the US Patent and Trademark Office (PTO) this week questioned the validity of a key Apple patent related to "pinch to zoom." And now Samsung has filed an emergency motion with the judge overseeing its patent-infringement damages trial against the consumer electronics giant.

"This [PTO] decision calls into question the entire jury verdict in this trial," the Samsung filing reads. "During its presentation, Apple made a deliberate decision not to separate the damages between the different asserted patents. Therefore, it will be impossible to determine what allocation of damages belong to the invalid patent versus the other patents."

Apple obviously disagrees with this assessment.

"Samsung's strategy to delay entry of final judgment in this case has crossed the bounds of reason," an Apple filing retorts. "Samsung seeks to halt the damages retrial in the midst of jury deliberations."

That latter technicality could ultimately sink Samsung's chances of prevailing here. But a dirty little secret of this and most other technology-industry patent battles is that the patents in question have never been effectively challenged. That is, many patents fail even a basic test of "prior art" comparison. And in the case of "pinch to zoom," specifically, it's pretty clear to the PTO that Apple didn't invent this technology and should not own the rights to it.

The sudden flare-up was triggered when the PTO issued an "Advisory Action" that deemed Apple's "pinch to zoom" patent to be invalid. And while Apple claims it can still contest this ruling, the PTO has said that its decision is final. The agency preliminarily declared the patent invalid in July, and Apple ignored an order to respond to the decision by the end of September.

"It would be unjust to have damages evaluated and awarded on a patent found to be invalid by the PTO," the Samsung filing adds. "Indeed, it may be an abuse of discretion not to issue a stay. Apple should not be permitted to waste the court's and Samsung's time. A stay is, therefore, warranted."

Earlier this week, the second trial in the case was sent to a jury.