What is the ruling on someone who broke their fast thinking the sun had set, and then it became clear that the Adhan was called before its due time, and what is the ruling on the muezzin in this case?

The muezzin who is negligent in verifying the sunset is sinful for failing to fulfill his trust. However, if he makes a mistake despite exerting his utmost effort, there is no sin upon him. As for someone who breaks their fast upon hearing the first adhan, believing the sun has set, and then it becomes clear that it has not, the view of the majority and the four Imams is that it is obligatory to make up that day. In contrast, Sheikh al-Islam Ibn Taymiyyah, the Zahiris, and a group of the Salaf hold that making up the fast is not obligatory, citing the hadith of Asma and the saying of Umar, may Allah be pleased with him: "Why should we make up when we did not lean towards sin?" and that the one who makes a mistake is not sinful. While this opinion has merit, the advice is to make up the fast because it is easy and involves no hardship, and it is the view of the majority.