Should be denounce one whom he saw eating by mistake in Ramadan?
Question

Some people say that if you see a Muslim drinking or eating out of forgetfulness during the day in Ramadan, you do not have to tell him, because Allah has fed him and given him to drink as it says in the hadith. Is this correct?
Praise be to Allah.Whoever sees a Muslim drinking or eating during the day in Ramadan, or doing anything else that breaks the fast, has to tell him off, because doing that openly during the day in Ramadan is wrong. Even if a person has an excuse for doing that, (he should not do it), lest people dare to do openly things that Allah has forbidden, i.e., openly doing things that break the fast during the day in Ramadan, claiming that they have forgotten that they are fasting. If the one who does that openly is sincere in his claim to have forgotten, then he does not have to make up the fast, because the Prophet (peace and blessings of Allah be upon him) said: “Whoever forgets that he is fasting and eats or drinks, let him complete his fast, for the One Who fed him and gave him to drink was Allah.” (Saheeh, agreed upon). Similarly, the traveler should not eat or drink openly among residents who do not know that he is a traveler, rather he should do that in secret so that they will not accuse him of doing something that Allah has forbidden and so that he will not encourage anyone else to dare to do that. And similarly, the kuffaar should be prevented from openly eating or drinking etc. among the Muslims, so as to prevent anyone taking this matter lightly and because they are not allowed to practise their false religion openly among the Muslims. And Allah is the Source of strength.