Round Corners?

As I'm playing around in photoshop for this personal project, I came across something: do we designers round the corner of the nav bar or statusbar?

From my observations, those with black statusbars are have rounded nav bars, while Apple's default mail app has no round corners for the nav bar, but it does have round corners for the statusbar that isn't black.

I tweeted @Max Rudberg for some advice on which should be rounded and he said: "statusbar". Short to the point!

Anybody care to comment? I feel like this is an inconsistency since some apps appear, like Instagram, with a "cupping" effect in your hand due to the round corners. Who here also believes that apps are designed apart from it, as opposed to designing the status bars with the app like I have done here?

All discussion just for fun and learning! Please jump in!