Updated February 20, 2016, at 10:40 a.m.

Apple CEO Tim Cook claims that if his company helps the FBI get into a dead terrorist’s iPhone, a precedent would be set that has “implications far beyond” this case. But is that true in the legal sense?

Technologically speaking, it should be possible for Apple to cooperate with law enforcement—as telecommunications companies have done for 100 years—in this particular case without compromising the tough encryption standards now baked into its phones. So the question then becomes: would this cooperation actually set an unwanted legal precedent for Apple?

Apple contends the feds are seeking an “unprecedented use” of the All Writs Act, a 1789 law that allows courts to issue orders that pertain to matters not yet covered by a law. But we’re not exactly in uncharted waters. As Kate Knibbs wrote on Gizmodo, the government has leaned several times on the All Writs Act to compel Apple and other communications companies to facilitate investigations. At least one judge has rejected a request on the grounds that the government can’t use the 1789 act to justify pretty much anything that Congress hasn’t yet explicitly allowed or disallowed.

Now Apple is betting that it can persuade a different judge to see things the same way—and that it's not, as the Justice Department contended on Friday, merely trying to protect its "business model and public brand marketing strategy.”

So how likely is it that the company wins this case? It's very hard to predict, says Orin Kerr, a professor at the George Washington University Law School who specializes in the laws governing computer crime. Kerr wrote in the Washington Post that previous rulings don't match well onto this case, largely because Apple is not a perfect analogue for the traditional telephone companies involved in past surveillance practices. "This case is like a crazy-hard law school exam hypothetical in which a professor gives students an unanswerable problem just to see how they do," Kerr wrote.

(Read more: Washington Post, New York Times, Gizmodo, Popular Mechanics, the New Yorker, KieranHealy.org)