Customer: "Our website is down."
Me: "No, its not down, its broken."
Customer: "Oh, that might have been me?"
Me: "You need to disable xyz plugin."
Customer: "But I cant get into the website."
Me: "You have FTP access you can do it that way. If not we can do it but we will charge you xyz for doing it."
Customer: "Oh, OK. Can you tell me what I have to do once I've FTP'd in?"