Has an AFL game ever ended 43-9?
Exactly once. On June 7, 1902, Sydney beat St Kilda 43-9, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 43-9 in league history.
That makes 43-9 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 44-9 has happened never and 43-10 has happened never.