It was just one slap.

In the context of the Bush administration’s post-9/11 torture program, one slap was practically nothing.

No big deal compared to, say, the punching and slamming into walls and stress positions that were part of the “interrogation” program. Not all that bad, compared to the sleep deprivation and hunger and ice-water dousings. You wouldn’t even call it torture, set against the prolonged waterboarding of a suspected terrorist or the actual death of a detainee who was left chained to a floor, half-naked in near-freezing conditions.

Just one slap. “A single slap to the face,” as the CIA-funded attorney for Spokane’s torture entrepreneurs put it.

However, in the ongoing trial of the two former Fairchild Air Force Base psychologists whose company earned more than $80 million to develop and carry out the enhanced-interrogation program, the slap is playing a big role.

It was administered by Bruce Jessen against Gul Rahman, who was being held in a secret CIA prison, as a means of testing Rahman’s resistance. Rahman died of hypothermia soon afterward, following days of harsh interrogation recommended by Jessen.

The slap pertains to the central question in the case: Were Jessen and James Mitchell guilty of breaking the law, as the ACLU alleges on behalf of three former detainees? Or were they simply doing what their government bosses had legally justified and told them to do?

In other words, are they personally liable?

The two men and their attorneys argue they are not. In legal filings, the attorneys claim the men were not the “architects” of the plan, as one CIA official described them, nor the decision-makers. Their attorneys have argued that their role in the CIA program didn’t have a “substantial effect” on any crime committed against the plaintiffs, and that the men have “derivative” immunity from prosecution because they were contractual employees of the government.

Mitchell and Jessen have each, in depositions, described being pressured intensely by CIA officials to push forward with torture when they wanted to stop.

Here’s how Jessen put it: “They kept telling me every day a nuclear bomb was going to be exploded in the United States, and that because I told them to stop I had lost my nerve, and it was going to be my fault if I didn’t continue.”

But the judge in the federal case against the men, Justin Quackenbush, poked several holes in the idea that they acted entirely under the direction of the CIA last week in a ruling allowing the case to proceed.

One of the big pokes involved the slap of Gul Rahman.

Rahman was a native of Afghanistan captured in Pakistan in 2002 in a combined U.S.-Pakistani operation, court records say. Jessen allegedly evaluated Rahman at a CIA prison in Afghanistan to see if “he was resistant and further torture would be required to break his will,” Quackenbush wrote in his memorandum opinion.

Over the course of a 48-hour period, Jessen interrogated Rahman and “at one point used the facial slap (enhanced interrogation technique),” the judge wrote. Jessen then determined Rahman was strong, focused and resistant, and recommended in a memo to his superiors that “environmental deprivations” and a “concentrated interrogation exposure regimen” be continued. Jessen left the prison, and the interrogation of Rahman continued; he was found dead, short-chained to a concrete floor in near-freezing temperatures and naked from the waist down, six days later.

Quackenbush cites the slap as an example of Jessen acting on his own and exercising discretion, and not simply following the direction of the CIA. It’s important to note that the judge was not issuing a final judgment on the question of liability, but noting that there is enough evidence for a jury to hear and decide the case.

“The finder of fact could find such testimony contradicts the defense assertions the CIA exercised absolute control over who would be subjected to EITs and which EITs would be used,” he wrote.

He raised a similar point with a decision Mitchell made to shorten the length of the “pours” during waterboarding – “further evidence Defendants exercised discretion in applying the EITs,” Quackenbush wrote.

Quackenbush’s decision to let the case proceed to trial came as a surprise to some, given how skeptically the judge had questioned plaintiffs’ attorneys in the case. But his memorandum took issue – sometimes sharply – with a variety of defense arguments that Mitchell and Jessen had some form of protection resulting from their contractual relationship with the CIA.

Quackenbush also rebuffed efforts to throw out as evidence the huge Senate Select Committee on Intelligence report on torture – which concluded the torture program was ineffective in obtaining intelligence and that the CIA had misled the public and Congress, among other criticisms. This is an interesting point, given that Mitchell’s and Jessen’s attorneys were making the equivalent of the conventional conservative argument against the report as biased because it was produced by a committee with a Democratic majority.

In rejecting the argument, Quackenbush outlined the level of depth and thoroughness of the SSCI’s inquiry, and noted: “Defendants’ assertion the Report is untrustworthy because 6 Republicans on the SSCI voted against it is not convincing.”

It’s a complicated, extraordinary case, and promises to be a complicated, extraordinary trial. A lot may rest on seemingly small things – a slap, a pour – in deciding how responsibility will be assigned between CIA headquarters in Langley, Virginia, and a company once headquartered in downtown Spokane.