Factual error: When Marylin Rexroth's ex-husband dies, she inherits his money because he had not removed her from his will after divorcing her. Under California Probate Code § 6122(a)(1), the dissolution of a marriage automatically revokes any disposition or appointment of property made by the will to the former spouse.
Continuity mistake: After Miles makes his keynote speech, he goes down the aisle and eventually Wrigley embraces him. W. is holding a program in his hand while hugging Miles. At first it is rolled up, then it is folded over, then it is rolled up again. At no time did he change it.
Continuity mistake: In the scene with Catherine Zeta Jones and George Clooney in the restaurant near the beginning of the film, we see CZT hold the glass by the stem but in the shot of her from behind the glass is held around the bowl.
Continuity mistake: As soon as George Clooney tears up his speech, we see it scattered on the podium. As he leaves the podium, we see his torn up speech placed neatly to one side, but the pieces are quarter-sized, despite only tearing them once. He walks down the aisle, then in the next shot from the podium watching him walk away, the papers are scattered again.
Continuity mistake: When George Clooney delivers his speech, his hair alternates between shots. In some shots he has a lock of hair carefully placed in the middle of his forehead while in others it is gone.
Continuity mistake: In the scene with Catherine Zeta Jones and George Clooney in the restaurant near the beginning of the film, we see numerous shots of CZJ alternating across the table with GC and her hair is different in all of them.
Audio problem: The producer sings along Simon and Garfunkel's "The boxer", but changes the lines "Just a come on from the w*ores on 7th. avenue" to "just a come on from those gals on 7th avenue". I'm sure the Coen Bros. did it deliberately. And strangely enough, when the song is played during the final credits it's the original text.