"Agent 4773 actually spoke to Ed Lee on the phone in the context of an illegal donation," Briggs said.
Breyer pressed Briggs on what the "context of an illegal donation" means.
"A bribe," Briggs said. But when Breyer pressed further, Briggs couldn't produce evidence directly linking Lee to criminal wrongdoing.
And the transcript of that alleged conversation was not included in Chow's original motion. Breyer has since ruled that all future references to "wiretap applications and orders, and the documents incorporated therein, shall be filed under seal and may be disclosed only upon a finding of good cause by this Court."
He said Thursday that the case includes some 100,000 pages of transcripts from FBI wires.
"There's nothing in the record that demonstrates that the mayor was involved in the contributions, or splitting it up, or that there was any impermissible quid pro quo," Breyer said.
Briggs said he inadvertently omitted the transcript of Lee's alleged taped conversation with the agent from the original motion, but he described it to reporters after Thursday's hearing.
"[Jones] said, here, somebody wants to talk to you, and the FBI says it was Ed Lee got on the phone, said thank you so much for your support. I'm looking forward to working with you or something to that effect," Briggs said. "Zula arranged a meeting a couple weeks later. Ed Lee sat down at that meeting with three undercover agents from the FBI and very carefully talked about potentially favorable contracts in the city ... and then he kind of disappears from the investigation."
The mayor's office did not respond to a request for comment, but a spokesman for Lee's re-election campaign did respond.
"Are you kidding me???" Ed Lee for Mayor 2015 Communications Director P.J. Johnston wrote in an emailed response. "The judge vindicated the Mayor, and you're pursuing more outrageous accusations by Shrimp Boy ... Shrimp Boy’s legal strategy was to smear as many other people as he could. The strategy failed. It’s incumbent upon the media to pay at least half as much attention to the exoneration as they paid to the scurrilous accusations."
San Francisco's Ethics Commission, district attorney and city attorney have launched investigations into the alleged improper campaign donations.
Chow's defense team said it didn't expect the case to be dismissed but had hoped the court would force the government to reveal how the decision was made to stop investigating Lee. With that discovery, the lawyers argued, they could likely make a better case that Chow was unfairly targeted while federal prosecutors turned a blind eye to Lee.
"We're in a Catch-22 unless the court intervenes," Serra told Breyer.
Assistant U.S. Attorney Susan Badger argued the legal burden is on the defense to provide evidence of a selective prosecution, which they failed to do in this case. She said in court that the issue goes to the heart of government separation of powers.
"The executive makes the decision who and what to prosecute, whether there is sufficient evidence," she said. "The courts require a rigorous standard in order to allow the judicial branch to start scrutinizing prosecutorial discretion."
Breyer suggested to the defense that Lee and others may not have been prosecuted because the evidence wasn't there.
"No, too big to fall," Serra responded. "Too big to fall."
"There's nothing there, Mr. Serra," Breyer said.
Serra said allegations brought up in the selective prosecution motion will be central to the defense's case when Chow's jury trial begins.
"They could have got other political people easy as pie," Serra said after court. "They chose not to, and this motion here, we wanted to find out really, why didn't you? Why didn't you go to the grand jury on the mayor? Why didn't you further the investigation? ... You're going to find that they didn't want to touch this very strong political core in San Francisco.