There is only a .003'' gap between the base circle and the rocker when propery adjusted. Normally the base circle will have little or no wear which indicates that there actually is some play bewteen the rocker and the and the cam shaft.
This one had no lash at all and the base circle shows heavy contact from rubbbing on the rocker. It may or may not have resulted in a burned intake valve. If it did burn through the valve, that's because intake valves are not designed to handle hot gasses like an exhaust valve can.