GetCurrentOrientationAndPosition(..) modifies Camera

Hi All,
I am trying to implement a 3rd person perspective Camera, that hangs off a camera boom.
This all aligned before I make any calls to obtain the rotation and position from the HMD.

This is seen in the following screenshots.
The screenshots show the player facing forward, and then the player facing right.
To perform the turn, I simply rotate the camera boom, of which the camera is attached.

As you can see, the ball is centered.

As soon as I call GEngine->HMDDevice->GetCurrentOrientationAndPosition(HMDOrientation, HMDPosition);
the rotation and position of the camera are altered.
This is without making any use of the returned orientation and position.

The following screenshots show the focal point as something other than the ball.

Does anyone know why this is happening?
Shouldn’t GetCurrentOrientationAndPosition(HMDOrientation, HMDPosition) only update HMDOrientation and HMDPosition?