Using cameraController.cameraOverlayView versus cameraController.view

Question

Say you bring up the camera on an iPhone:

self.cameraController = [[UIImagePickerController alloc] init];
[self presentViewController:self.cameraController animated:NO completion:NULL];

It's easy enough to add a button to that. But interesting you can do THIS:

UIView *examp = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"smiley"]];
[self.cameraController.view addSubview:examp];

OR THIS

UIView *examp = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"smiley"]];
self.cameraController.cameraOverlayView = examp;

They both work perfectly in testing.

However will often see it mentioned that if you change anything, other than using camera.OverlayView, Apple will reject it:

https://developer.apple.com/library/ios/documentation/uikit/reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html

As a curiosity, in fact has anyone ever had an app rejected when adding a subview to the .view? Any insights?