In the word of one former aide in the room, Kane was left "flabbergasted."
That tense briefing was a defining moment in what has become an ugly and very public fight between two powerful personalities.
On its face, the battle is about whether Kane made the right call in shutting down the sting investigation without bringing criminal charges.
But fueling the clash is a history of rancor and suspicion two years in the making between a career prosecutor and an up-and-coming political star.
Kane, 47, won her job in November 2012 with an 812,000-vote margin to become Pennsylvania's first elected female attorney general. Until the controversy over her decision to shutter the sting, she was widely considered "the rock star of the Democratic Party," political pollster and analyst G. Terry Madonna said.
Fina, 48, is the prosecutor who brought virtually every high-profile case handled by the office in recent years - winning a slew of political-corruption convictions that helped propel his onetime boss, Republican Tom Corbett, into the governor's office.
Neither Fina nor Kane would agree to an interview for this article.
To Kane's team, Fina was, at best, a man juggling far too many cases. At worst, it viewed him and his tight cadre of state anticorruption prosecutors as self-righteous and contemptuous of any supervision.
Look no further, the Kane team says, than Fina's decision to hand over the sting case to federal authorities, giving Kane no chance to evaluate it or her alleged conflict.
"The law is well settled," Kane said at a news conference this month. "Another prosecutor cannot decide a conflict for me. I have to decide my own conflict."
From the perspective of Fina's allies, he is a tireless professional who galvanized the Attorney General's Office into putting away corrupt politicians from both parties. His determined and aggressive style earned him the nickname "Sonny," after the oldest son in The Godfather.
Fina's supporters believe Kane unfairly tarnished that record by treating Fina and one of his biggest cases - the Jerry Sandusky child sexual-abuse investigation - as a campaign prop.
Kane, they assert, has demeaned Fina at every turn. No sooner had she taken office, they say, than Kane ordered Fina's computer hard drive secretly removed in a bid to gather evidence on how he conducted the Sandusky case.
Even after Fina left the Attorney General's Office, his allies say, Kane tried to muzzle him at a convention of his fellow prosecutors. Then, they say, she handed over his office e-mail to a Pennsylvania State University supporter, which they say violated the typical privacy afforded law enforcement communications.
And in the debate over the sting case, they say Kane has falsely painted Fina as having bungled the investigation and engaged in racial profiling in the selection of targets.
The feud in recent weeks has become openly toxic.
"This investigation was half-assed," Kane said of Fina's sting at a news conference this month.
Though Fina declined to comment for this article, that comment from Kane did spur him into giving a response.
"She just gets more pathetic," he told the Allentown Morning Call. "It's embarrassing for law enforcement."
The tension between Kane and Fina was sown in 2012, when Kane came from behind to win the Democratic nomination to run for attorney general.
Fina, with a law degree from George Washington University, had been a prosecutor for two decades, and had tried more than 100 cases.
By 2012, he and his team had brought corruption charges against more than two dozen state legislators and aides in the "Bonusgate" and "Computergate" cases, including two former House speakers, one from each party.
At the time, Kane was a little-known prosecutor making her first run for public office and running a polished campaign that ended in a landslide victory.
A graduate of the Temple University law school, Kane had worked for a dozen years as an assistant district attorney in Lackawanna County, where she specialized in child-abuse cases.
By the time she left the office in 2007, she had tried two dozen cases.
As a candidate, Kane zeroed in on an issue that had roiled Pennsylvania: the investigation of Sandusky, the former Penn State assistant football coach. Her questioning of the investigation resonated particularly with a Penn State alumni network convinced that the university had been unfairly denigrated.
Fina had run the Sandusky investigation, which unfolded in 2009 while Corbett was attorney general and in 2010, when Corbett ran for governor.
Kane's chief criticism was of Fina's decision to put multiple victims and witnesses before a grand jury rather than arrest Sandusky after his first accuser came forward in 2009. Charges were not filed until late 2011.
"Never once have I put a case like that in front of a grand jury," Kane said during her campaign. "Never once would it have taken three years for me to take a pedophile off the street."
If elected, she pledged, she would investigate the Sandusky investigation.
Fina's supporters insist he was right to take the time to build a case in which multiple victims provided corroborative accounts of Sandusky's way of "grooming" and molesting his victims.
Veteran prosecutor Joseph E. McGettigan, who joined Fina in the courtroom to try the case against Sandusky, said an early defeat with a weak case would have chilled other victims - and emboldened Sandusky.
"If you're going to go after a big target, you've got to bring a big gun," McGettigan said.
In summer 2012, Sandusky was convicted of molesting 10 victims and given a sentence that should keep him behind bars for life.
Later that year, Fina charged three administrators, including Penn State's former president, with a cover-up, saying university officials put the school's reputation above the safety of children.
Once Kane took office, she quickly carried out her campaign pledge, hiring a former federal prosecutor to, in effect, reinvestigate Fina's Sandusky investigation.
That inquiry has been going on for more than a year. Kane recently announced it had been delayed by, among other things, a time-consuming effort to retrieve e-mail.
Kane has said there is nothing personal about her dispute with Fina, whom she rarely refers to by name. "I do not have any animosity towards the lead prosecutor in this [sting] case," she said.
Still, in speaking with reporters, Kane has suggested Fina fueled a furor over the sting investigation to damage her credibility and blunt the impact of the coming Sandusky report.
"The criticism against me is not only unfair, but it's suspect," Kane said. "I will tell you it is the same prosecutor - it bothers me, and I hope there's not a link - that we are investigating as part of the Sandusky investigation."
Fina's supporters dismiss Kane's assertions.
An alleged conflict
Kane's first week in office was Fina's last. Things started badly and got worse.
Within hours of Kane's swearing-in ceremony, technicians on her staff went into Fina's office, after hours, and seized the hard drive from his computer. Their goal was to gather material to assist in the Sandusky inquiry.
Fina discovered the seizure the next day, when he went to turn on his computer and couldn't.
He was furious - "a raging bull," according to one person who witnessed Fina's reaction.
Just hours later, Fina finally came face to face with Kane in a conference room at the Attorney General's Office to debrief her and her staff on the biggest public-corruption cases.
It was the first and last time Fina and Kane were to meet professionally.
According to sources, Fina was calm but blunt.
Ticking off the top 10 cases, he eventually briefed her on the sting investigation, which involved an undercover operative who had worn a wire and taped elected officials pocketing cash and gifts.
At the briefing, Fina told Kane she faced a conflict: two of her campaign supporters - Philadelphia Common Pleas Court Judge Daniel D. McCaffery and campaign professional Josh Morrow - had had dealings with the sting's undercover operative, Tyron B. Ali.
Before he became a confidential informant in the sting investigation, Ali had arranged, through straw donors, to give $10,000 to McCaffery's 2009 political campaign, secretly pledging to reimburse them, according to people close to Kane, Fina, and Ali. He gave the checks to Morrow, then McCaffery's campaign manager.
At the time, McCaffery was seeking the Democratic nomination for Philadelphia district attorney, a race he lost to Seth Williams.
McCaffery has said that when his campaign discovered the straw donations, it reported them to the Attorney General's Office and cooperated with law enforcement officials looking into the matter. No charges were ever filed in connection with the straw donations.
Fina believed Kane should not be in a position to make decisions on Ali or the sting case because of her associations with McCaffery and Morrow.
Though McCaffery had briefly run against Kane for the Democratic nomination, he dropped out and supported her campaign. And she tapped him to be the master of ceremonies at her inauguration. She made Morrow her 2012 campaign spokesman.
At the briefing, Fina told Kane that because of the conflict, he had referred the case to federal prosecutors in Philadelphia. They never took over the case.
Kane has said she faced no conflict. She has said that she wasn't close to McCaffery or Morrow, and that there was no evidence to suggest the two men had known the donations were from straw donors.
Fina went to federal prosecutors on his own authority without checking with Kane's predecessor, Attorney General Linda L. Kelly, sources say.
Kane's first deputy, Adrian King, said he was astounded that Fina believed he had the authority to make such a decision on his own.
"Does anyone realize the absolute chaos that is going on here because someone has decided that they are free to do whatever they wish with files in this office?" King asked reporters during a recent news conference.
He added: "Frank Fina may have opinions, and he is free to have them. But this is why we have elected government. This is why the people choose someone, to exercise their judgment on a case."
Even after Fina left the Attorney General's Office, he and Kane seemed locked in a circle of discord.
In February 2013, Kane unsuccessfully sought to block Fina and McGettigan from speaking at a meeting of the state district attorneys' association about their successful prosecution of Sandusky, the Legal Intelligencer reported. Kane has denied that.
That same month, Kane reversed the policy of the previous attorney general and agreed to give a blogger some office e-mails written by Fina concerning the Sandusky investigation.
Blogger Ryan Bagwell, a 2002 Penn State graduate who believes the university community was unfairly tarred by the Sandusky scandal, sought the e-mails under the state's open-records laws.
Kane's office last week released even more Fina e-mails, according to Bagwell.
And there is the sting case. The debate over her decision to shutter it aside, a new front has opened in that battle: whether Fina's new employer - the Philadelphia District Attorney's Office - can take on the case and possibly prosecute the elected officials caught on tape.
Madonna, the political analyst and pollster, said in an interview last week the fight between the attorney general and Fina's allies had turned personal because the stakes were so high - particularly, he said, for Kane, whose name is often mentioned for higher office.
"I think this thing has developed a life of its own," he said. "And once that happens, it's hard to separate the personalities from the endgame - and the endgame is not to lose."