I'm new to all things WP but I was trying to make pretend calls on the focus s last night at the Microsoft store and I kept hitting the camera button. Kind of annoying. Maybe it's because I'm a lefty?
It want matter. When you put the phone to your face it will put the screen to sleep, and a quick press of the camera button will no longer do anything anyway.
The focus s has a really odd placement for the camera button in my opinion. I'm a righty and I keep hitting the camera button too. After awhile you learn to hold the phone so you don't activate the camera.