How the Apple-Samsung jury split the difference

November 22, 2013, 4:38 PM UTC

Courtroom sketch by Vicki Behringer via ABC News.

FORTUNE — The  Apple v. Samsung jury that awarded Apple $290 million in damages Thursday has started to talk, and they’re telling a pretty simple story.

According to two jurors who spoke to Bloomberg News, the jury took its cues from one particularly credible Apple (AAPL) witness — a Chicago CPA named Julie Davis who offered them a clear roadmap to a verdict.

In its opening statement Apple had divided the damages it was seeking into three baskets:

  • $35 million in lost royalties on the patents Samsung infringed
  • $230 million profits Samsung made on the infringing devices
  • $114 million profits Apple lost when customers bought Samsung’s phones instead of Apple’s
  • Total: $380 million

Davis explained in detail what the numbers meant from Apple’s point of view. Although she was a substitute witness hired after Apple’s first accounting expert died, Davis kept her cool under tough cross-examination by Samsung, according to jurors. They call her a “superstar witness.”

Jury form. Click to enlarge.

On two of the three baskets — lost profits and lost royalties — the jurors agreed that Apple should get everything it asked for.

On the third — Samsung’s $230 million in profits — they “butted heads,” according to Colleen Allen, the former U.S. military medic who served as forewoman.

Samsung had argued that there were operating costs associated with those profits — $178 million, to be exact — and that to be fair the jury ought to reduce Samsung’s profits of $230 million by $178 million.

Allen didn’t buy it. She agreed with Davis that “absolutely none of it should come out,” because Samsung hadn’t provided evidence to show that all those operating costs were associated with the devices at issue in the case.

Other jurors argued that making the devices must have cost something. Since they had no way of calculating what that was, they spit the difference, cutting Samsung’s $178 million in half. Here’s the math:

  • $35 million lost royalties
  • $114 million lost profit
  • $230 – ($178/2) = $141 million net Samsung profits
  • $290 total award

Of the $1.05 billion Apple was awarded in August 2012, the company is now owed  $929 million (Thursday’s $290 million plus $639 million that was not part of this trial).

In March, when Judge Lucy Koh ordered the retrial, the line most news outlets took was that the Koh had tossed out 45% of Apple’s billion-dollar award. Pending appeals, it looks like Apple is going to get closer to 90 cents on the dollar.