The reason the Night Fox knew the passcode is because it was his security warehouse and passcode. At the beginning of the movie, the gang attempt to steal a document from a safe only to find out that somebody has already beat them to it and stolen the document.

Why did LeMarc betray Toulour?

In Ocean's Twelve, Toulour wants to embarrass Danny and impress his mentor, LeMarc. ... Toulour then secretly tips off Danny's team about a heist job in Amsterdam, which he plans to do himself, just so that he can show off.

Why is Bruce Willis uncredited in Ocean's 12?

Bruce Willis, who appears as himself in the film, was originally signed to play Danny Ocean in Ocean's Eleven (2001), but pulled out due to scheduling conflicts.