Maybe I've been getting this wrong...
I read the exception to say that a batter who has just been retired for the first or second out on strikes where the third one was dropped (i.e. 1B was occupied), is not causing interference just because she runs to first and F2 makes a DMC and throws to first.
However, if she then gets hit with said throw, then she has interfered with the defenses ability to put out the other runner and, despite the exception, is still guilty of interference and should cause the runner closest to home to also be out. And in this case, I wouldn't care if in the running lane or not.
Am I off the reservation?