This could be true. Technically. You don't need to work with NSA, you may, for example, work with some another organisation tightly coupled with NSA. There also

This could be true. Technically. You don't need to work with NSA, you may, for example, work with some another organisation tightly coupled with NSA. There also could be carefully planted vulnerabilities in the software, it would be extremely stupid for Apple to implement clearly recognizable backdoor. And of course they will deny anything always.