Indian chief's signal

An Indian chief is driving his Cadillac somewhere at Nevada. Suddenly his car gets broken. He examines it, and reveals that a technician must be called. But the chief has only $4, and no credit card (unfortunately B-) ). So he gathers some wood, makes a fire and signals his tribe with its smoke: "Hey, send somebody to my location with $500!" The tribe accepts this signal, but to make sure in its meaning, signals back - once again, with the smoke:

"OK, chief, but why so much ?"

At this moment a ground test of nuclear bomb is being held on the test field nearby. A huge mushroom-like cloud of smoke rises into the sky... The tribe signals:

"Ok, Ok, chief, we just wondered, why to be so angry?"