Doesn't it clamp it to 0.7V below the supply not 0.7V above the supply?
Some of the biggest shocks I've had have been from playing around with transformers and large contactors. The moment you disconnect the battery from the relay the same current will cary on flowing, for an instant, and if you're in that current path it isn't nice. Currents above 5mA are considered harmful and can potentially kill you, however in practice when you interrupt the 20mA goint through a relay it only passed through you for a split second so it isn't too bad. but a big contactor with a current of 2A is a different story.