Jack cannot handle the thought of Tiger passing him. Jack is probably the most pompous ass in the game and this game has its share of pompous asses. He will do anything he can to try and make the inevitable seem unimportant. Tigers the best ever, Jack better get use to that.
This is one of the biggest reason's Arnie was such a fan favorite back in the day and is still a legend today. One would think that bother Jack to no end as well, and you know for a fact that if it were Arnie's record Tiger was chasing he would be cheering all the way.