Is 'law guy' a thing?

The New York Times tells me something I didn't know: Apparently, it's common to refer to an appellate specialist as "the law guy." From the story, "At End of Sheldon Silver's Corruption Trial, the 'Law Guys' Take Over", by Benjamin Weiser:

But it was clear late on Thursday, with the parties and the judge seated around a conference table and the jury not present, that Mr. McDonald and Mr. Kry [a prosecutor and a defense attorney] had critical roles as legal specialists in the case—"the law guys," as several experts put it—a role the public rarely hears about.

The law guys must master the legal aspects of the case, and be steeped in precedents and in issues that might become the focus of an appeal or need to be responded to in court at a moment's notice.

The Times continues:

The role of the "law guy" is like that of an assistant to a football coach who stands on the sideline, knows the rules better than anyone else and says, "Challenge the call."

The term law guy is an anachronism from a time when the legal profession was dominated by men; women now frequently serve in that role, said Deirdre von Dornum, attorney in charge of the federal public defender's office in Brooklyn. "I love to be the 'law guy,' " she said.

On the defense side, the law guy is often a seasoned appellate lawyer who is brought into a case for that expertise.

In the United States attorney's office for the Southern District of New York, law guys are typically junior prosecutors who may have little or no courtroom experience, but bring a freedom to think deeply about the legal issues because they do not have the day-to-day burden of conducting a trial.

I certainly understand the role of an appellate specialist and legal expert. Different lawyers have different skills. In important cases that raise tricky legal questions, it's often smart to bring in someone with appellate expertise and legal firepower.

But I have to confess, I'm new to the specific phrase "law guy." Is it a common phrase that I just missed? Or maybe it's a New York thing? Or maybe it's not a common phrase, but it was added to spice up an otherwise dry story about legal arguments in a high-profile case? Because you may not care about the correct mens rea to apply to the quid pro quo of a bribe in an honest services fraud case, but maybe you'll care about the life and times of "the law guy."

UPDATE: On Twitter, NPR Justice Correspondent Carrie Johnson writes:

Never heard this before in years and years covering courts https://t.co/RuMJbzDnhe

- Carrie Johnson (@johnson_carrie) November 23, 2015

ANOTHER UPDATE: On the other hand, New York criminal defense attorney Scott Greenfield writes by e-mail that it's a "common old school usage" in New York, "where we have 'trial guys' and 'law guys.'" He also points to this post of his from 2007 which used the distinction. So maybe it's a New York thing after all.