I've looked this up extensively on the web but nothing seems to answer this question satisfactorily. For example, here's Wikipedia's answer. I try thinking of it considering the properties of a conductor in electrostatic equilibrium. The charge on a conductor in equilibrium resides on the surface and the electric field is zero inside. Okay... But once lightning hits a metal cage with a person inside, isn't the cage momentarily NOT in electrostatic equilibrium? Isn't the cage not in electrostatic equilibrium until the charges are done redistributing themselves, and in this period of time, won't the person inside be fried?