Is it permissible for the oppressed to supplicate against the oppressor even if he is not certain of his being an oppressor?

It is permissible to supplicate against an oppressor whose oppression is confirmed, as evidenced by the hadith of Sa'id ibn Zayd, who supplicated against a woman who wronged him, and Allah answered his supplication. This is also supported by Allah's saying: "Allah does not like the public utterance of evil speech, except by one who has been wronged." Ibn Abbas and Qatadah interpreted this verse to mean that it permits the wronged person to supplicate against their oppressor. However, if the wronged person is not certain of the oppressor's injustice towards them, it is not permissible to supplicate against them. Nevertheless, forgiving the oppressor is better.