Repeating the pronouncement of divorce thrice intending to let the wife hear
If the reality is as you mentioned; that the man
said to his wife, "I divorce you, then I divorce you, then I divorce you", the ruling is: This is a major irrevocable divorce (the third and final divorce, after which the man can only remarry the woman if she remarries and that marriage ends lawfully), so his wife is forbidden for him until she marries another person in a real marriage and not Tahlil marriage (a fake marriage to return to her first husband). As for the claim that he repeated the words of divorce just to let her hear it and did not intend to divorce her thrice, it is not acceptable because the words of divorce were mentioned in a sequence that does not refer to any confirmation. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.