Reachability with iPad cellular issue

I’ve discovered an issue with Reachability, not sure if it’s a bug or not. If the iPad has a cellular modem, Airplane mode is ON and Cell Data shows ‘Airplane Mode', Reachability (See attached) returns true, as if it can reach the Internet. But when I try to load a site I get back a DNS error, can’t resolve the site. If I turn off cellular data and have Airplane mode ON I get false from Reachability (as one would expect). Does this sound like a bug or is the Reachability class missing something?

Here is a sample of how I call Reachability:

if(Reachability.IsHostReachable("www.google.com"))
{
    var url = new NSUrl("some web site");
    var urlRequest = new NSUrlRequest(url);
    webView.LoadRequest(urlRequest);
}