But he may be on his way out anyway.
While a source with direct knowledge of the closed-door talks declined to say what exactly was under discussion, CNN affiliate KGTV, citing anonymous sources, reported that the mediation was "designed to include a review of a potential resignation."
Though the city chief of staff changed the locks on Filner's office during his time away, it was to preserve evidence rather than to keep him out, the city attorney's office has said.
The office also said it could seek, as a "last resort," a restraining order -- saying Filner creates a hostile environment for women -- to prevent him from returning to work, the Los Angeles Times reported.
Then there is the effort to gather signatures for a recall election, giving voters the options to kick Filner out of office if he won't go voluntarily.
Armed with clipboards and pens, volunteers hit the streets of San Diego over the weekend to begin collecting signatures for a recall effort. They need more than 101,000 signatures by September 26.
"We're going to be everywhere. We're going to be at sporting events. We're going to be at street fairs, arts shows -- you name it, we will be out there," Dave McCulloch, an organizer, told KFMB on Sunday.
The accusations against Filner trace to his 20 years in Congress and his time, since his election in 2012, as mayor.
They have spurred many -- including from fellow Democrats, such as California's two U.S. senators -- to urge the now 70-year-old to resign. The Democratic National Committee will vote on a resolution this week calling on Filner to do that as well, according to a draft copy obtained by CNN.
But that's not to say he doesn't have his supporters.
They include some members of some labor unions and Latinos, who claim Filner is being denied due process and that the recall effort is orchestrated by those who oppose his political agenda.
On Monday, some of them held a "We Will Not Be Silent" rally, also outside City Hall.
Still, the pro-Filner faction is clearly in the minority.
Roughly 81% of city residents want Filner to resign, according to a poll conducted by KGTV. Another CNN affiliate, KFMB, reported local radio hosts hired skywriters to spell out "Surrender Bob" over areas of the city last week.
Those sentiments were voiced, loud and clear, in protests outside City Hall.
"There is no excuse for abuse, and there is no excuse for you to stay in power," attorney Gloria Allred, who has attended the mediation sessions, told the crowd.
His accusers include a singer at a campaign fundraiser and Jackson, who has called him unfit for office. Shannon, a 67-year-old represented by Allred, was the latest person to accuse Filner.
"Every day that I went to work, I had butterflies in my stomach because I did not know what was going to happen the next time the mayor came by my desk," she told reporters last week.
"I have three sons, four grandsons and two great grandsons. As our mayor, you should be -- but are not -- a role model for any of them," Shannon said.