Unless there is more to the incident than reported in the article that you provided, the title of your post seems to allude that the two pilots have been fired (sacked). The article states that the two pilots seem to have been temporarily grounded while the investigation is conducted
Qantas has since launched an investigation into the dispute between the two pilots who have been told they cannot fly.
The managers were later informed of the argument between the pilots and stood them down.
Does "sacked" mean something else down under?
Btw - 20 hour duty day.