I'm not a racist. Nor are the rules.

[C. Cecil Ivanish]

At what point did the SC have a membership card? He showed CCI his Italian ID and offered to let CCI hold it while he went in the club.

Here:

SC seems puzzled. Then rummages in his pockets. Produces... yes. You guessed it. a membership card.
SC: "I just wanted to see if you are racist, and now I know you are! I'm never coming back and I'll tell all my friends!", and walks away.

What really gets me is the fact that the first time he played the race card was when you told him he was entitled to half off the price of membership.

Good point.
Maybe he was insulted by being given a preferential treatment only because of his nationality? Any non-Italian had the same discount, though, any.
Mah.