Apple documentation incorrect about MKMapView -regionThatFits: ?

Question

In the Apple documentation for the -regionThatFits: method of the MKMapView, it says that this will return a new region centered on the same point as the region that's passed in, only with the regions bounds corrected for the iPhone screen aspect ratio. This seems to be incorrect in implementation...before the call to this method, my region shows up as:

$5 = {
  center = {
    latitude = 37.322898864746094, 
    longitude = -122.03209686279297
  }, 
  span = {
    latitudeDelta = 14.278411865234375, 
    longitudeDelta = 1.5202401876449585
  }
}

..however, after the call to this method, I end up with:

$6 = {
  center = {
    latitude = 36.973427342552824, 
    longitude = -122.03209686279297
  }, 
  span = {
    latitudeDelta = 14.521333317196799, 
    longitudeDelta = 14.0625
  }
}

This is quite a big difference on the map - this translates to the distance between Cupertino, CA and Santa Cruz, CA. Anyone else experience this discrepancy?