Introductions?

Oh, I have a question... when did Joseph(Billy Zane) ever introduce himself as "Joseph" to Sean. I mean it came absolutely out of the blue when Sean yells "You know what, Joseph, this is fun". And even if he happende to glimpse his name on the contract, wasn't it a major blunder of the production crew to not let him introduce himself when speaking to Sean in the beginning( which he didn't)?