Is it permissible to exploit the mistakes of a Muslim employee who harms his colleagues by reporting him to officials and the government, knowing that this may lead to his dismissal?

It is permissible for the oppressed to complain and seek justice for themselves from the one who wronged them, based on the Almighty's saying: {Allah does not like the public utterance of evil, except by one who has been wronged}, and the hadith of Hind, Abu Sufyan's wife, and Al-Nawawi's statement on the permissibility of mentioning a person in a way they dislike if it is for seeking a fatwa or making a complaint. Likewise, whoever becomes aware of treachery or deception must inform the person in charge of the company about it, as this falls under the category of offering sincere advice.