The New York Knicks may have celebrated their first NBA championship in more than five decades on Saturday (June 13), but not every fan left Madison Square Garden in a festive mood. A video circulating on social media appears to show a lone San Antonio Spurs fan wearing a Dennis Rodman jersey and attempting to fight a large crowd of Knicks supporters inside Penn Station following New York's Game 5 victory. The footage, shared by the Instagram account Diaper_Man_Official, shows the man shoving several people, chasing others, and throwing multiple punches as Knicks fans surround him and shout from all directions. At one point, a police officer steps in and attempts to calm the situation before escorting the fan away as members of the crowd continue to taunt him. It is unclear what sparked the confrontation or whether anyone involved was arrested or injured. The chaotic scene took place after the Knicks defeated the Spurs to win the NBA Finals 4-1, securing the franchise's first championship since 1973.…