Why was The US Government(State Department) Fined $400 (Not US)for Littering at the end of the 1970's as a result of a major event?

Multiple pieces of Skylab have been found in the sparsely populated grasslands of western Australia. Nobody was injured. But the U.S. State Department received a $400 fine for littering from the authorities in the town of Esperance, Australia.

In a similar incident , Canada sent the U.S.S.R. a bill for $6,041,174.70 USD, half of which the Soviet government paid after three years of negotiations.

I saw on another link which I didnt save, the fine has never been paid!

My original link

Bedstor,

An Australian municipality, the Shire of Esperance, fined the United States $400 for littering.[2] In 2004, the History Channel documentary "History Rocks" stated, in an episode covering major events of 1979, that this fine has never been paid.
Wikipedia