Has an AFL game ever ended 91-49?
Exactly once. On May 10, 1998, Richmond beat Melbourne 91-49, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 91-49 in league history.
That makes 91-49 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 92-49 has happened 3 times and 91-50 has happened 4 times.