According to Apple:
“The FBI wants us to make a new version of the iPhone operating system, circumventing several important security features, and install it on [the shooter’s] iPhone,” Cook added. “In the wrong hands, this software — which does not exist today — would have the potential to unlock any iPhone in someone’s physical possession.”
According to police and witnesses and families and friends: 15 innocent people were killed and a warrant was issued to get as much information as possible about the murdering scumbags who did.
They weren't expecting "sorry we can't hep you" as an answer, especially with that whole 4th amendment thing and all aside from it would have been something MOST companies would have done. And I'm sorry, but they were just being asked to defeat the destruction feature by removing the number of times the password could be tried on THIS ONE PHONE. Not exactly a national threat to keeping pictures of your dog humping your Uncle Ernie's leg form going public.
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.