be let off

To be pardoned, released, or allowed to escape from blame, responsibility, obligation, or difficulty. At first, Sam was suspected of stealing money from the safe, but he was let off after security camera footage showed it was someone else. You were let off with a warning, instead of getting a ticket? Boy, you got lucky. Considering he completely destroyed Mr. Smith's hardware store and dang near killed a few people, I can't believe he was let off with just three months in jail.