iPhone 6 Plus camera rotation problem - any way to fix it?

I took 7 photos this evening with my new iPhone 6 plus. All were taken in landscape mode. All were taken standing, holding the camera in landscape position pointed straight ahead or at a slight tilted down angle to shoot something relatively low in height.

3 of the photos came out oriented correctly. But 4 came out rotated incorrectly. And there doesn't seem to be a way to correct the rotation in the Photos app, is there?

Why don't the photos consistently turn out rotated correctly in the Photos app?

In the Camera app itself, I looked at each one after shooting via the little window that appears after taking each photo. In all those views the photos were oriented correctly.

A bug? Anything I can do to fix it?

Thanks,

doug