Alex Jones did not, as far as the evidence we have seen, harass the parents. Alex Jones did not direct anyone to harass the parents.
Some of his viewers used Jones' statements as justification for harassments.
Interestingly, as far as I know, nothing was pursued against the people harassing the parents. They went after the rich guy saying lies they didn't like, then depended on the fact no one besides the defense wants to side with someone who says such shockingly vicious lies about the facts surrounding dead kids.
the lies they didn't like lead to the harassment, it's not at all complicated
free speech doesn't absolve you of responsibility for the damages your words cause, despite not causing them directly
The defense - including Jones himself - also did a very poor job, so it's debatable whether anyone at all wanted a different outcome.