Much has been made of Gov. Gavin Newsom’s decision to attend a dinner party earlier this month at the pricey French Laundry in Napa County despite his daily pleas urging Californians not to congregate during the latest COVID-19 outbreaks. But with photos surfacing recently of the get-together that the governor’s office had said was outdoors, the gathering raises another quandary: What exactly constitutes outdoor dining? And, definitions aside, what’s safe?

With winter approaching and bringing with it chilly, wet weather, restaurants already struggling to survive what seems like a never-ending pandemic say the guidance hasn’t been clear. And it’s more important than ever, with most counties moving back this week in the state’s reopening roadmap to the most restrictive purple tier, which only allows outdoor dining.

Dan McCranie, owner of the Ladera Grill in Morgan Hill, said he understands the latest changes for restaurants but is disappointed by both the rules and the decision-makers.

“I think our county and state medical executives are making the best decisions they can with their current understanding of the virus. Having said that, I do tire of being lectured to by science-challenged bureaucrats (and) putting up with the arrogance of our political establishment, who assume that they are so elevated in stature that the rules simply don’t apply to them.”

“Gov. Newsom falls into both of those line items,” McCranie said.

When asked what constitutes outdoor dining, the state’s public health department pointed to guidance for restaurants, which mentions outdoor dining but doesn’t explicitly define it.

Individual counties can also create their own, more specific rules. Santa Clara County, for instance, says that outdoor dining spaces must either be uncovered (umbrellas excepted) or have at least half the perimeter open. That means a tented outdoor dining space must have at least two sides open to allow for free air flow, which helps limit the spread of the deadly disease. Alameda County also outlines specific guidelines for outdoor restaurants — giving businesses several options, including a shade structure “minimally open” on three sides to allow airflow.

Newsom’s office said before the photos surfaced on Fox’s Los Angeles TV station that the dinner in question was outdoors, but the pictures show a space with a roof and what appear to be at least three solid walls. The fourth wall appears to be a sliding glass door that was open at least part of the time, but when the party grew too loud it was reportedly closed. It’s worth noting that while Napa County, where the French Laundry is located, is now in the purple tier, it was in a lower tier when the dinner occurred, meaning some indoor dining was allowed. The governor’s office did not respond Wednesday morning to a request for comment.

Napa County and the French Laundry also did not immediately respond to questions about what constitutes outdoor dining there and about whether the restaurant considers the space where Newsom dined to be indoors or outdoors.

“I think it was bad judgment and terrible optics,” said John Swartzberg, professor emeritus of infectious diseases and vaccinology at UC Berkeley, pointing out that the virus is spreading more rapidly than in the past. “Eating with other people now is much more dangerous than a few months sago and a few months ago was dangerous.”

In terms of the actual science, there really is no clear line between what’s safe or unsafe in terms of outdoors versus indoors.

“It’s a continuum and the more airflow is restricted, the more indoors-y they behave,” said UCSF infectious disease expert George Rutherford of restaurant setups. “The safest is to be in an open field and spread out…as you add walls you’re less likely to dissipate potential airborne particles into the atmosphere.”

Researchers at Stanford and elsewhere have found that full-service dining is particularly risky, with the coronavirus spreading easily indoors, particularly where diners linger without masks as they eat.

Even when there is clear county policy about what’s allowed or not, restaurant owners still have to navigate city bureaucracies.

Helen Nguyen, who owns two Pho Ha Noi restaurants in Santa Clara County, one in San Jose and one in Cupertino, applied in both cities to get approval to put up a canopy over her outside dining areas.

She said the city of San Jose has streamlined the process, so she got a swift OK from those officials and already has a canopy in place on Story Road.

But the city of Cupertino’s application process has been more challenging, she said. Two of her blue summertime umbrellas fell down in high winds at that De Anza Boulevard location, so she urgently needs an awning there and is awaiting approval.

“Yesterday, I didn’t have customers,” Nguyen said. “They didn’t allow me to put the canopy yet. We only had pickup and to-go.”

San Jose chef-restaurateur David Wiesner says his outdoor dining approach these days is simple: “Tell me the rules and I will obey them.”

At his Siena Bistro in the Willow Glen neighborhood, he is trying to protect his guests from inclement weather with two structures, a walled patio and a tent.

But he wonders: “If air flow is the key, who decides how much air flow is needed? And are they enforcing any of this?”

In Santa Clara County, the rules on outdoor dining have been in place for months, but county officials nevertheless are sending reminders to the approximately 7,000 restaurants and food purveyors as they inform them of the new purple tier prohibition on indoor dining.

It’s primarily a matter of education, said Mike Balliet, the county official who is currently overseeing the Business Engagement Outreach Team.

When they receive a complaint from a consumer that a restaurant is, for example, operating with an outdoor tent that is “completely enclosed,” Balliet said they research the restaurant’s compliance paperwork, review the rules with the owners and ask them to make the necessary changes.

“The vast majority of businesses want to do the right thing,” he said. “Once we’ve approached them typically they do.”

Check back for more on this developing story.