I recall that in Android if an app doesn't release control of the camera then no other app can access it until the phone is rebooted. I suspect this is what was

I recall that in Android if an app doesn't release control of the camera then no other app can access it until the phone is rebooted. I suspect this is what was happening here. AFAIK, it isn't a bug with the phone hardware etc. just poor os design. Hopefully they'll fix it one day. Ref: 'Release the Camera - After using the camera, your application must properly release it for use by other applications.'