Has an AFL game ever ended 91-78?
Yes. AFL has seen a final score of 91-78 6 times. It first happened on May 6, 1933, when Essendon beat St Kilda, and most recently on July 21, 2019, when West Coast beat Melbourne.
That makes 91-78 the 342nd most common final score out of 6,607 that have ever occurred in AFL. One point away, 92-78 has happened 5 times and 91-79 has happened 6 times. At one point the score disappeared for 29 years, between 1933 and 1962.