The officials did not have royal honor to protect. So they were willing to learn from what had happened and to let the men go.
Pharaoh resisted again. He wanted to protect his public honor. He said the men could go only if they left their families behind. In this way, he hoped they would be forced to return.
Moses had never said they would come back. They said they were going into the wilderness to worship God. But once slaves are free, they do not willingly return to those who oppressed them. Pharaoh understood this.