Seems as long as you have a raised lip that is higher than the camera lenses, and the raised lip is sturdy enough then the rear protection is okay for most open cases. Haven't seen any examples of a case with raised lip around the plateau causing damage to the plateau when dropped. If you want to be even safer, added a skin to the plateau (e.g. XtremeSkins) to help prevent scuffs/minor scratches.
I don't rate the TechWoven for drop protection overall though, it seems to have poor front/screen protection especially if you use a screen protector as the lip/edge around the screen isn't very high.