As I understand it if he was acting consistent with his practice before the campaign (which I’d guess he was), then that is a defense against the idea that he had her paid because of the campaign, which would make it a legal payment.
At most, Stormy may only have become a threat to come forward because of the campaign, but if his regular practice was to pay off such women when they came forward it wouldn’t be considered a campaign payment at all anyway.
“At most, Stormy may only have become a threat to come forward because of the campaign....”
It is all moot anyway - he used his own funds, which is well within the law.