[nixpulvis]

Here's a crazy hypothetical for some mulling...

Let's say an abuser does use this, and goes on to track someone and then kills them (or commits some other very serious crime). The cops get involved, they start looking into it and discover (through a lapse in other privacy elements of this technology) that a third-party's iPhone was the one that gave away the location.

What are the third parties' legal defenses from the law to avoid being labeled an accomplice here?

[Nasrudith]

They don't need one. An accomplice is a person who knowingly, voluntarily, or intentionally gives assistance to another in (or in some cases fails to prevent another from) the commission of a crime.

The judge is going to be very annoyed at the incompetent prosecutor for wasting his time improperly trying to try anybody and anything connected to the actual actor as an accomplice.