Lucy Koh is chewing someone out again.

Anyone following the Apple v. Samsung patent trial has noticed the frequency with which Koh, the U.S. district judge presiding over the case, has scolded lawyers from both sides.

The most vivid example came last week, when Apple lawyers notified Koh that they wished to cram a large number of witnesses into the remaining few hours they had to make their arguments. This would have added to the mountain of paperwork and generated more work for Koh and her staff.

"Come on," Koh told Bill Lee, one of Apple's lawyers. "You want me to do an order on 75 pages? Unless you're smoking crack, you know these witnesses aren't going to be called."

The news media went wild. Typically, judges don't sound this informal. Koh, however, is not a typical judge and Apple v. Samsung is not the typical patent case.

Rookie judge

For starters, Koh is only 43, on the youngish side for a district judge, and not very experienced. She has been a federal judge for two years. Before that, she served two years as a California Superior Court judge in Santa Clara, Calif.

So as Koh prepares today to oversee final arguments in the case, a couple questions one might ask are these: did she know what she was doing, and did she mess anything up? The only things hanging in the balance are billions of dollars and possibly the future of the mobile phone and tablet businesses.

Apple claimed in a lawsuit filed last year that Samsung pilfered design ideas and some of the technology behind the iPhone and iPad. Samsung denied this and later filed its own suit alleging Apple infringed on some of its patents. Both sides want damages and if Apple wins, the company will want the court to force Samsung to cease the sale in the United States of the infringing phones and tablets.

The challenge for Koh was to ride herd over two famous and massive companies and their legion of attorneys -- some with equally massive egos. Naturally, with so much at stake, both sides would try to test the rules and she would need to keep them in line. If she was intimidated, she never showed it.

When John Quinn, founder of Quinn Emanuel Urquhart & Sullivan, one of the country's best known law firms, rose to request that Koh reverse an earlier decision to exclude some of Samsung's evidence, the two got into a confrontation. But she stood her ground, told the lawyer the issue had been covered and demanded he knock it off.

"Mr. Quinn, don't make me sanction you, please," Koh said. "I want you to sit down!"

Strangely, Koh isn't nearly as tough talking when she's not wearing the robe, say people who know her.

"When you meet her outside of the courtroom, she comes across as shy," said Mark Lemley, a law professor at Stanford University as is Koh's husband, Mariano-Florentino Cuéllar. "You don't expect her to be a tough courtroom presence but she's been every bit of that in the couple years she's been on the bench."

Is Koh biased?

In her legal career, Koh has done plenty of unexpected things. She's the first Korean-American to serve as a federal district judge and prior to that, she was a patent litigator. Legal experts say that it's rare for a patent litigator to be appointed to a district judgeship.

Koh handled patent and trade secret litigation for tech companies when she was a partner at McDermott Will & Emery in the mid 2000s. This part of her background raises the question that fans of Apple and Samsung have asked since the trial started: Is Koh biased? Does she have it in for one company or the other?

In 2006, Koh was part of a team of McDermott lawyers that represented Creative Technology in a patent dispute against Apple, according to The Washington Post. The case was settled with Apple agreeing to pay Creative $100 million. Some Apple fans accused her of favoring South-Korea-based Samsung because she's Korean.

But earlier this year after she hit Samsung's Galaxy Tab 10.1 with a preliminary injunction, fans of that company said her background as a Silicon Valley lawyer meant she was in league with Apple.

Nonsense, said Brian Love, a law professor at Santa Clara University who has followed the case. He points out that if Koh "were biased or had it in for one of the companies, she could have ruled against whichever one it was on summary judgment. Instead, she is sending the case to the jury.

Don't waste time

All these conspiracy theorists should consider the bigger picture and applaud Koh, say Love and Lemley. At a time when politicians lament government waste, Koh is a taxpayer's dream.

The public got Koh on a big discount, according to Love. To become a district judge, she took a huge pay cut, he said. She works nights and weekends and has cut vacations short so she can get back to work. In Apple v. Samsung, she has become well known to the lawyers in the case for clock watching. Both parties were given a maximum number of hours to make their arguments. If a lawyer waxed on for too long, Koh docked time.

She has stunned lawyers by calling for the next witness to be sworn in with only a couple of minutes left to go in the day. She stressed a simple message: don't waste the jury's time. They have lives to return to. Don't waste her time because there are literally hundreds of other cases waiting for her.

If she seemed short tempered, it was likely because someone wasn't using time wisely or creating what she considers unnecessary paperwork. As the two sides filed motion after motion, exhibit after exhibit, Koh and her staff likely felt buried under an avalanche of documents.

Love says Koh has two law clerks and two administrative assistants working for her.

"Counting herself, that's five people," Love said. "Compare that to the number of lawyers for Apple and Samsung. They each have dozens of lawyers filing documents, seemingly every day and all night long. It's incredibly natural for Judge Koh to be frustrated at the lawyers when you consider the deluge of paper being filed...The reality of federal court is that she doesn't have the manpower to deal with all this."

For keeping up with all of it and for maintaining order in the case, Love and Lemley give Koh high marks.

"She's done a great job," Love said. "There's many big personalities in the room, big names. Her job was to keep them under control and keep them moving and she did that."

CNET writer Josh Lowensohn contributed to this report