Example: validation of serialized data followed by deserialization. Deserialization properly should throw a checked exception, since invalid serialized data is very much a thing. But in this case the serialized data is known to be correct (because it passed validation). The checked exception will never occur, and were it to, there's nothing we could do about it, because it reflects a logic error, same as out of bounds array access.

The algebraic data type equivalent of this shows up all the time in functional code -- unwrapping a result type you know can't be Error/None/etc. because of logic. You don't rewrap it and force the caller to deal with a case which logically cannot occur; instead you throw an unchecked exception.