Deliberate mistake: When Jack fights the impostor, they are roughly the same height, but when the impostor is revealed to be Angelica, she is suddenly much shorter than him. (00:21:30 - 00:23:50)
Revealing mistake: When Jack Sparrow is chased in London, being on the carriage and looking back to his chasers, you can see the broad tire tracks of a modern vehicle in the mud. (00:16:55)
Continuity mistake: When the movie ends, Barbossa is given his hat with no feather. A frame later the feather appears. (02:04:55)
Answer: Although this has been a running gag throughout the series, the filmmakers probably felt it quite didn't fit into the storyline or else thought the joke had simply worn itself out. It may also have been intended to be used for promoting the film and in theatrical trailers.
raywest
It should have been kept in. I thought it was funny.