What is the ruling on followers continuing with an imam who joined the Shaf‘ and Witr prayers without informing them, and what is the ruling on one who gave the salutation or glorified Allah? And was the imam required to inform them of his action?

Connecting the even (shaf') with the odd (witr) is permissible, and separating them is also permissible. One who connects the even with the odd should not sit for the middle tashahhud so as not to resemble the Maghrib prayer. The Imam should alert the congregants when connecting if they are accustomed to separating. Whoever follows the Imam in the aforementioned connection, their prayer is valid, based on the Prophet's (PBUH) saying: "The Imam is appointed to be followed." Whoever concludes the prayer (by saying salam) has a valid prayer according to Ashhab of the Maliki school. And whoever says "Subhanallah" (glorified be Allah) to the Imam, believing there to be a mistake, their action is correct, based on the Prophet's (PBUH) saying: "Whoever experiences something during their prayer, let them say 'Subhanallah'."