The only actual legal structure protecting Ive's position at Apple is one in which Cook voluntarily complies with Jobs' stated wishes. That is to say, there is nothing stopping Cook from firing Ive tomorrow, changing his job title or control inside the company. Jobs may have also secured the board's agreement to protect Ive, but that too would rest merely on their voluntary compliance with such. In the corporate world, there's no such thing as a truly untouchable employee. The CEO, the board, or shareholders, someone can always get rid of you.