After Eddie fills out the competition on the cereal box, he edits it slightly and declares that his final answer is 'Hot girls, skimpy knockers, look out everyone!". In fact, after removing the words he mentions, his actual final answer would be "bloody hot there, that's why. What a stupid question. besides, there's lots of birds knocking about the beach, wearing skimpy bikinis, knockers hanging out for everyone get a good look.
Also, he mentions removing the words 'the' and 'is'. Those words were never in his original answer.
When Richie has finished the small talk with Monica, he tries to undress her, but struggles with the bra, complaining that he doesn't know how bras work as he's never seen one before. However, in act 1, when we first meet Monica, she isn't wearing any clothing, and as Richie would have been unlikely to have asked Eddie for help, it stands to reason that he would have been the one to put the bra on Monica in the first place.
During the second phone call to the solicitor, Eddie mistakenly says the amount owing is £10,000 when it should be £15,000.