if(finished) was causing this exception:

```*** Terminating app due to uncaught exception 'NSRangeException', reason: 'Cannot remove an observer <SDCSegmentedViewController> for the key path "title" from <UIViewController> because it is not registered as an observer.'```

`finished` is not always true, but it is only called once per call to `transitionFromViewController`, this causes unbalanced add/remove leading to the above crash.

(if you add try/catch around the calls in```stopObservingViewController``` you see additional errors about unbalanced view animations, in addition the view you are moving to sees an additional `loadView` call)