Name a worse one. That was an excellent team and Niagara was Niagara
Niagara was a meaningless road loss in a historic season and SJ was forced to rely on a freshman point guard called Mark Jackson who wasn't very good because their starting PG was injured. Bad losses happen all the time. Reggie Carter, Bernard Rencher and Wayne McKoy lost by 13 to Columbia in 1978. David Russell, McKoy, Billy Goodwin and Kevin Williams lost to Princeton at Alumni Hall. Bootsy, Postell, Barkley and Glover lost to Samford.
Malik Sealy losing to Tulane in the NCAA tournament was a much worse loss than dopey Vermont and in a meaningful game. If I had to pick one game, it's Chris Mullin, David Russell, Kevin Williams, Billy Goodwin and Bill Wennington losing a first round NCAA tournament at Nassau Coliseum, which was about the worst loss in program history.