Narration known as 'Audio Description' was, in error, set as the default audio track when this episode was first released on the Paramount+ streaming service in the US. AD is an optional service specifically designed to help blind and partially sighted consumers enjoy audiovisual content. However, a lot of people unaware of this, thought it was superfluous scripted narration and were largely annoyed by it.
Sister Andrea sprayed Leland Townsend with Holy Water and he was instantly burned. Later Sister Andrea poured the remaining 'Holy Water' back into a bottle of Ammonia cleaner.
Ammonia has an intense, acrid and unique smell. It would be obvious that it was not Holy Water.
Ben manages to recover the email cache from the priest's computer and uses the '@' hack to email the last person who was emailed from the computer. He could of simply checked the sent items folder.