Will someone who consorts with his wife after a triple divorce, or someone who acted upon an incorrect fatwa out of ignorance, be punished for zina or for his shortcomings in knowing the Shariah ruling?

Whoever commits a sin and then dies upon faith before repenting, his matter is up to Allah the Almighty. It has been narrated from Ubada ibn As-Samit (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever amongst you fulfills (his pledge), his reward is with Allah. And whoever commits any of these sins and is punished for it in this world, that will be an expiation and purification for him. And whoever Allah conceals (his sin), his matter is up to Allah; if He wills, He will punish him, and if He wills, He will forgive him."

Therefore, whoever cohabits with his wife after divorcing her thrice, while knowing this, he is an adulterer. A fatwa (definition) does not permit what is inherently forbidden. He must offer sincere repentance, for the one who repents from a sin is like one who has no sin. He must distance himself from the woman he divorced thrice until she marries another husband through a legitimate marriage of desire, not a tahlil (analytical) marriage, and then he divorces her after consummation. Only then is it permissible for him to remarry her. However, if he dies before repenting, it cannot be asserted that he will be punished; rather, his matter is up to Allah the Almighty.