Has an AFL game ever ended 28-23?
Exactly once. On June 24, 1989, Essendon beat Footscray 28-23, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 28-23 in league history.
That makes 28-23 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 29-23 has happened 3 times and 28-24 has happened 1 times.