Is what was said by the father—reprimanding the driver and the housemaid and making implicit accusations—considered Qadhf (slanderous accusation of unlawful sexual intercourse) that necessitates seeking forgiveness, especially since he did not explicitly use the word Qadhf and did not have evidence or four witnesses?

It is obligatory to verify news and not to hold people accountable based on ill-suspicion, as Allah the Almighty says: "O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin." And He says: "O you who have believed, if there comes to you a disobedient one with information, investigate, lest you harm a people out of ignorance and become, over what you have done, regretful." It is not permissible to accuse a chaste person, whether male or female, of indecency. A chaste person is one against whom the act of indecency has not been proven. If the driver and the maid appear righteous, it is obligatory for the father to repent to Allah, apologize to them, and seek their forgiveness. His question to the driver, "What were you doing?" is not an accusation warranting a [legal] punishment, but rather ill-suspicion and an emotional injury, both of which are forbidden, even if they do not reach the degree of slander.