API v1: Error type not appearing in Swagger schema

[frewsxcv]

Looking at the error shape here, it looks like:

{
  "error": string | object,
  "status": number
}

But if we look at the Swagger file for V1 API, this is the specified error type:

"Error": {
  "type": "object",
  "properties": {
    "code": {
      "type": "integer"
    },
    "message": {
      "type": "string"
    }
  }
}

But in the code I also see this exists which has the correct shape.

So are there really two different kinds/shapes of errors that can get returned from the V1 API? And if so why isn't that reflected in the schema?