Last I heard those gene editing things lead to so called of-target edits, so they were basically corrupting random dna. Now in this case the baby would have die

Last I heard those gene editing things lead to so called of-target edits, so they were basically corrupting random dna. Now in this case the baby would have died without this treatment so clearly benefits outweight the risks. But even then they probably want to have the dose be as low as possible. But I'm speculating a bit here.