Objective-c MKAnnotationView.rightCalloutAccessoryView has a memory leak

Question

I was doing some leak testing, and I found a leak that's been really bothering me. I have a MKMapView allocated, and some MKAnnotationView's on the map. The code that leaks is in the MKAnnotationView's initWithAnnotation:

self.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];

When I comment that line, the code no longer leaks.

This leak only happens when the annotation is selected, so I added:

if ([_mapView.selectedAnnotations count] == 1) {
  GBAnnotation *test = [self.mapView.selectedAnnotations objectAtIndex:0];
  [_mapView deselectAnnotation:test animated:NO];
}

In my MapController's dealloc method (I am using ARC, but the dealloc method also removes observers, and sets the mapview's delegate to nil). This works for a while, but it leaks when only the user's location blue dot is showing. I'm also doing everything correct in the delegate method:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation;

The objects that Instruments is telling me that are leaking are a UIButton, a UIImageView (which looks like the imageView of the button), and then a bunch of UIKit, and QuartzCore library objects.

I'm using Xcode 5.0.2, supporting iOS 6 and 7.