Looks like my memory was right.
"In 1968, the Ohio State Buckeyes, en route to a national championship, defeated their bitter rival, the Michigan Wolverines, 50-14. Late in the game, Ohio State held a commanding 44-14 advantage and scored one final touchdown. Rather than taking the more common extra point kick, Ohio State head coach Woody Hayes opted for a two-point conversion, which was unsuccessful. When asked later why he went for two points, Hayes said, "Because I couldn't go for three!", though players have commented that there was some sort of confusion on the extra point kick, and Hayes was just covering for his players. The comment came back to haunt Hayes as Michigan would upset Ohio State the following year, 24-12, spoiling a bid for another national championship."