Reference: Fataawa Ramadhaan – Volume 1, Page 227, Fatwa No.173
Fataawa as-Siyaam libni Jibreen – Page 15
Question: If I see a man eating during the day in Ramadhaan and I know he is eating out of forgetfulness, do I remind him or not? Some people say: “Don’t remind him because Allaah is the one who has provided this food and drink for him”.
Response: It is upon you to remind him because this is from commanding the good and forbidding the evil. If you saw him eating then it would be upon you to command him to refrain (from that) as this is from commanding the good and you should forbid him from eating as this from forbidding the evil. Also, in him stopping eating prevents the onlookers from thinking he is being neglectful of the rulings of the Sharee’ah by the suspicion generated through his forgetfulness.