You may be on to something. As there whole thing smacks of desperation, I wouldn’t be surprised if some corners were cut. However, the CNN article didn’t identify the person who “gave” permission, nor say that person didn’t have authority.
Per the article “Investigators have scrutinized the actions of various individuals who were involved, including Misty Hampton, a former Coffee County elections official who authored the letter of invitation referenced in text messages and other documents that have been turned over to prosecutors”.