Has an AFL game ever ended 80-19?
Exactly once. On June 21, 1902, Fitzroy beat St Kilda 80-19, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 80-19 in league history.
That makes 80-19 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 81-19 has happened never and 80-20 has happened never.