I say, and with God's success: If he is certain that he did not perform the inhalation, his washing is incomplete, and he must perform the inhalation to complete it, and his prayer is not valid, so he must repeat it, and he should inform the people about the repetition of the prayer unless the lack of inhalation is valid according to a recognized school of thought, in which case he is not required to inform the people, especially if it causes fitna (temptation or discord). And God knows best.