The US Patent and Trademark Office has tentatively decided that all 20 claims in Apple's US Patent No, 7,469,381 are invalid

The non-binding decision had Samsung sprinting off to Judge Lucy Koh late Monday to inform her of the re-examination finding.

See, Apple used Claim 19 of the so-called rubber-band patent to nail Samsung's hide to the barn door this summer, one of five patents that made a California jury award Apple landmark damages of $1.05 billion against Samsung for infringing it in various products including the Galaxy Tab and Galaxy S2 smartphone.

Fortune recalls that it was supposed to have been one of Steve Jobs' favorite patents, the widgetry that convinced him that Apple could make a meaningful dent in the cell phone market, and something he distinctly told Samsung not to copy although it did anyway.

The PTO's reappraisal could persuade Judge Koh to overturn at least part of the jury's verdict and save Samsung millions.

The PTO tentatively found that Claim 19 was anticipated by a 2003 European patent filed by Luigi Lira and, ironically, a never-asserted Apple patent filed in 2010 by Bas Ording, Scott Forstall et al.

Forstall is the Apple SVP whose deposition describes Claim 19 as: "Say you are scrolling something and you get to the end of it, as your finger descends down you pull it farther away from the edge and then when you let go, it bounces back."

FOSS Patents, which discovered the Samsung filing with Judge Koh, says there's no telling when the PTO will make a final determination. There are a number of appeal steps between now and then, including the Court of Appeals for the Federal Circuit but a really final determination could happen after any appeal and make the patent unenforceable.

FOSS says Samsung has had a rubber-band workaround for about a year and if the patent proves unenforceable Samsung will go back to what it was doing originally.

The ‘381 fallout could also benefit HTC, which is waiting for a ruling from the International Trade Commission late next month on different claims of the patent. Apple also got an injunction against Motorola Mobility based on the European version of the ‘381 patent.

FOSS isn't at all surprised by the ‘381's problems. It says it's "a great achievement in the realm of use interface psychology, but in a strictly technological sense it has extremely little merit, if any. It's a patent on a great idea and out-of-the-box thinking...But it doesn't take rocket science to make it work. Technically it's just about drawing rectangles."

See http://www.fosspatents.com/2012/10/patent-office-tentatively-invalidates.html.