When Elaine and Joel go to the Giants football game, stock footage is shown of the Giants and the Minnesota Vikings. Later, stock footage is shown of the Giants playing the Eagles.
When Joel & Elaine are at the football match, the player making the tackle for the Eagles is #99, Jerome Brown. Jerome Brown died in a car accident on June 25, 1992 so couldn't have been playing in that game.
Jerry (Jerry Seinfeld) tells Elaine (Julia Louis-Dreyfus) that Joel Rifkin strangled 18 people. He was only responsible for 17 murders.
It was Elaine (Julia Louis-Dreyfus) who left the ticket for Kramer (Michael Richards) at the stadium, not Joel (Anthony Cistaro). So it would have been Elaine who was summoned over the loudspeaker rather than Joel.
Kramer (Michael Richards) wants to get into the football game, but back in season 6.12, The Label Maker (1995), Jerry (Jerry Seinfeld) stated that Kramer only likes Canadian football.