The 4-3 vote denying Gascon that option was accompanied by disagreement among some commissioners about what the agenda item they were voting on actually meant.
The item would authorize Gascon to develop changes to the police department's general order to include the use of conducted energy devices, widely known as Tasers, and to develop policies and training practices to go along with that order.
While Gascon and some commissioners said this merely meant giving him permission to draft a Taser policy that would then later have to be approved by the commission at a future hearing, Commissioner Petra DeJesus, who said she opposes the introduction of Tasers, described it as "vague and ambiguous."
"It's putting Tasers in, it's putting them in tonight," she said.
Commissioner David Onek disagreed.
"We are not voting to approve Tasers tonight," Onek said. He said the vote was to ask the chief to draft a policy about Tasers "and to bring it back to us, where then we would vote for it, or not vote for it."
Onek said he would only approve Taser use for the department under a "very, very, very restrictive" policy introduced by Gascon.
"I think that he deserves the deference to come up with a plan," Onek said.
An apparently exasperated Gascon acknowledged that the agenda item could have been written more clearly, and said he could have begun drafting a Taser policy before bringing it to the commission, but did not do so "out of an abundance of caution."
Gascon added that it was well within the commission's ability to amend the item, but no amendment was offered.
In the end, commissioners Joe Marshall, Thomas Mazzucco and Onek voted for the proposal, and commissioners DeJesus, Vincent Pan, Yvonne Lee and Jim Hammer voted against.
Hammer, who was widely regarded as the swing vote on the commission and who attended a news conference held by Gascon last week in support of Tasers, said tonight, "I remain in favor of changing our use of force policy. I remain in favor of adding something to that, and that may be Tasers."
But the issue needed a "full vetting," Hammer said.
"I will not rush into this tonight," he said.
The commission gave nearly five hours of debate to the issue Wednesday night - mainly from advocates warning of the potential dangers of Taser use - and another several hours two weeks ago, where testimony centered on arguments for their implementation.
The devices, which deliver a powerful electric shock, rendering a person temporarily without muscle control, are controversial. They have been implicated as a contributing factor in some deaths and serious injuries during arrests by police. Opponents also say they are unregulated by any governmental agency.
Gascon has said Tasers represent a "less lethal" addition to the department's arsenal that would decrease the number of injuries and fatalities for both officers and suspects. He has also said that his officers would receive "very in-depth, Fourth Amendment training" on their use, and they would only be employed against aggressive, violent suspects.
Hammer expressed particular concern about the rights of mentally ill suspects who engage in violent encounters with police.
Encounters with armed suspects intending to commit "suicide-by-cop" often end with officers defending themselves with a firearm and killing the suspects, police say. In some of those cases, Tasers would present a potentially non-lethal option, they argue.
Hammer did allow room for an "incredibly limited policy that could walk that fine line between reducing deaths and injuries, and not intentionally killing people who don't deserve to die."
Many of Wednesday night's speakers opposed to Tasers also argued community and civil rights groups, as well as mental health advocates, had not been part of the discussion leading up to the vote.
"If we vote this down tonight, then the policy dies," Mazzucco cautioned his fellow commissioners before the vote.
It remained unclear following the vote whether Taser use by the San Francisco Police Department could be revisited in the near future.
"I don't know," said Gascon as he left the hearing room.