Has an AFL game ever ended 42-22?
Exactly once. On August 18, 1900, Carlton beat Melbourne 42-22, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 42-22 in league history.
That makes 42-22 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 43-22 has happened never and 42-23 has happened 1 times.