I remember a game against the Sixers around that same period. Dr. J was winding down his career and the rivalry was no longer an even match. The Celtics, and certainly me as a fan, were suprememely confident that they could beat the Sixers at will, but still relished the opportunity to do so. The Sixers had kept it close, but Larry went to the line in the final moments with the Celtics up two. Game over!
Larry missed both free throws and Dr. J. canned a game winning 3 on the other end. One of the biger jaw dropping losses I can remember. Larry was indeed human.
Edit: This was during the 1986 season and ended a 14 game win streak!https://youtu.be/ch8yNP8Uhiw