I still say they'd be better off replacing the director than the writers. Strip the scene with the helmet gizmo down to the dialog, and it's hard to blame the writers.
The director could have staged the scene in a lot more believable way without changing a word of the dialog, which is the bulk of the writer's contribution. For one, the director could have staged the thugs in a way that makes it harder for Supergirl to employ her known powers to safely rescue Mon El. For another, the director could have put Cyborg Hank in the scene to prevent Supergirl from getting any stupid ideas. Instead, we get Supergirl released from her cage with nobody even covering Mon El with a firearm. That's on the director.
I'm not saying the writers are innocent, because there are plenty of times when the show suffers from conveniently forgetting Supergirls' powers, but not all of the tactical blunders are on the writers' side. And even if the writers turned in such a detailed script, the director has a responsibility to make it look right during shooting.