The three judges who heard the Justice Department’s appeal in a case called United States v. Ali Shaygan knew full well how consequential their ruling would be. The government wanted the appellate court to overturn a Miami federal judge’s imposition of $602,000 in sanctions for the U.S. Attorney’s prosecution of Shaygan, a physician accused of illegally writing prescriptions for controlled substances. And as Judge Pryor wrote in the majority opinion in the case, the issues on appeal were profound: “They involve the sovereign immunity of the United States, the constitutional separation of powers, and the civil rights and professional reputations of two federal prosecutors.”

That’s why it’s so compelling that the Eleventh Circuit’s ruling came down to an interpretation of the word “or” in the Hyde Amendment of the 1998 Appropriations Act. The Hyde Amendment says federal judges can sanction prosecutors when “the position of the United States was vexatious, frivolous, or in bad faith.” The majority in the Shaygan case — Eleventh Circuit judge William Pryor Jr. and Fifth Circuit judge Rhesa Barksale, sitting by designation — decided that the government’s prosecution of the doctor wasn’t vexatious or frivolous, so by definition it wasn’t conducted in bad faith. The majority vacated the $602,000 attorneys fee award, as well as a public reprimand of two of Shaygan’s prosecutors. But in a dissent, Chief Judge James Edmondson said the Hyde Amendment’s plain language means a prosecution can be undertaken in bad faith even if it isn’t vexatious or frivolous. He found Shaygan was prosecuted in bad faith, so the district court’s $602,000 fee award should have been upheld.

Shaygan’s lawyer, David Markus of Markus & Markus said he plans to ask the entire Eleventh Circuit to review the ruling en banc, and, if that is denied, to appeal to the U.S. Supreme Court. “The way Judge Pryor tried to rewrite the statute — the Eleventh Circuit or the Supreme Court is going to be very interested in that,” he told me.

Here’s the backstory. Shaygan was a pain-management specialist who came under government scrutiny when one of his patients died after taking a combination of methadone and illegal drugs. Shaygan was indicted for trafficking in illegal prescriptions. His lawyer, Markus, moved to suppress Shaygan’s statements to investigators, arguing that his client had asked for a lawyer before making the disclosures. Assistant U.S. attorney Sean Cronin warned Markus that the motion to suppress was going to result in a “seismic shift” in the case against Shaygan.

Sure enough, the government soon obtained a 141-count superseding indictment. And unbeknownst to Markus or his client, prosecutors began a side investigation of allegations that Shaygan was secretly offering patients money to influence their statements to investigators. Prosecutors signed up one of Shaygan’s former patients as a confidential informant and enlisted him to tape conversations with Shaygan and Markus.