Has an AFL game ever ended 100-89?
It has. 100-89 has been a AFL final 3 times in 16,622 games. The first was Essendon beat Sydney on April 18, 1970; the latest was Fremantle beat Richmond on June 3, 2006.
That makes 100-89 the 1534th most common final score out of 6,607 that have ever occurred in AFL. One point away, 101-89 has happened never and 100-90 has happened 5 times. At one point the score disappeared for 31 years, between 1975 and 2006.