Yeah, it is totally possible that an originally ineligible player could establish contact with an opponent within 1 yard of the NZ, and drive him to 3 yards beyond the NZ and let him go; no foul. But, if he keeps driving the opponent beyond 3 yards, or initiates contact more than 1-yard beyond the NZ, and the pass crosses the NZ, then, yes, either of those scenarios is OPI. Might get an ineligible downfield call before OPI, if the pass is nowhere in the area where the pass comes down.