1. We want to guarantee our work is not a "derivative work" of anything Apple wrote.
2. If we look at any Apple binaries, there's no way prove that our code didn't borrow from Apple.
3. Since we didn't look at any Apple binaries, then there's no way our work can be a derivative work-- we didn't even look at their stuff.
The legal framework around all this is way too immature to make a definitive statement one way or the other. Anyone who says otherwise is speculating.
The only way to clarity will be legislation or court cases, because it really could go either way.