What is the ruling on a husband's speculative statement that God sent fleas upon the people of Pharaoh, and is his action considered major or minor disbelief, and is his saying "this is not forbidden" an act of making the forbidden permissible, and what are the implications of that?

Not every statement made about Allah without knowledge is considered disbelief (kufr), nor does everyone who forbids what is lawful or permits what is unlawful or issues a fatwa without knowledge become a disbeliever thereby. Nor does everyone who utters disbelief (kufr) leave the fold of Islam until the conditions for declaring someone a disbeliever are met and the impediments to doing so are absent. Lice (al-qaml) have been mentioned in the exegesis of the verse as small flies. Declaring a specific person a disbeliever is not a simple matter; it is impermissible to speak about it based on conjecture and suspicions. Only people of knowledge should speak on it. Furthermore, one whose Islam has been established with certainty does not lose his Islam except with certainty.