A government attorney, defending a financial fraud law used to prosecute a fisherman for destroying undersized grouper to avoid paying a fine, underwent blistering and sometimes derisive questioning by U.S. Supreme Court justices on Wednesday.

“What kind of mad prosecutor would try to send this guy up for 20 years [in prison] or risk sending him up for 20 years?” asked Justice Antonin Scalia, referring to the criminal penalty that Capt. John Yates faced under the post-Enron law known as the Sarbanes-Oxley Act.