I thought that Scott Free was from some guy named Scott (last name) who "got off" for something due to a technicality... I should have paid more attention in high school.

Well, there was a very famous man named Dred Scott whose later life centered around his struggle to escape slavery, and marks one of the most embarrassing legal cases in United States history. He sued in federal court to become a free citizen based on the fact that he has lived for significant periods of time in free states. When the case eventually got to the Supreme Court, the court found not only against Mr. Scott, but that, as a slave, he didn't even have the right to bring a case in federal court. The decision also voided the Missouri Compromise, which had prohibited slavery in new states north of Missouri. All of this was likely a significant impetus to the US Civil War.

But Mr. Scott was never granted his freedom by the US judicial system. He was eventually freed by his owner, only to die a year later of tuberculosis. So I don't think that using him as a frame of reference for freeness is appropriate.

Not that you suggested that this was what you based this on. But it's the only Scott case that I can think of.