They also refused to make a build (signed by Apple) which would remove any of those protections, though technically possible, but would have tainted their produ

They also refused to make a build (signed by Apple) which would remove any of those protections, though technically possible, but would have tainted their products as backdoored. They were prepared to argue forcing them to do that would be the government compelling speech, a violation of the First Amendment, a precedent the FBI didn’t want, and so turned to a CellBright type service instead. Apple did make public statements at the time against backdooring devices which might be construed as a stance.