The first question would be 'Why, his lawn and not everyone else's???" I don't believe their P and K has much to do with it and SOM is really quite good... Does he mow during the heat? Does he apply herbicides during the heat of Summer? Was it Fescue? Full sun should be KBG and should be given a chance to go dormant with dignity when the excessive heat comes on... I've read that Fescues do not go dormant, but actually die... however it takes a lot more to kill a good stand of fescue... Is he on sand???
Now that I know that clay's texture(platelets) has nothing to do with water infiltration, percolation, or drainage,,, I wonder what does...