Is the first divorce that took place approximately thirty years ago, in which the husband was angry and there were no witnesses, considered a legitimate divorce or not?

If the anger was slight and did not affect the husband's will, then his divorce is valid. However, if the anger was severe, then the divorce of an unlearned person (عامي) who did not seek a fatwa from anyone, and it later became clear that his divorce occurred in severe anger, does not take effect. He may reconcile with his wife during her waiting period (iddah) or by a new contract after its expiry. As for the student of knowledge (طالب العلم) or the seeker of a fatwa (المستفتي) who was given a fatwa that the divorce is valid, his divorce is valid, and he is not permitted to reconsider it. Deceptive measures to reconcile after the third divorce are forbidden.