Got a response from HTC
"As for your inquiry about removing the default selection when using the Best shot feature in the camera. This can be done by going to your home screen, drag down the Notification bar, select Settings, Apps, and then tap on the App tab. From this list, select Gallery, Clear data (do not worry this will not delete any pictures), OK, and then tap on Clear Defaults. Once you have done this, go back to your home screen and open the camera and test."
It worked and didn't lose anything.