First, only IELTS examiners under exam conditions can give you a proper score. Anyone giving you a band score outside the exam is not a proper IELTS examiner. If they are examiners and Cambridge finds out, they will get fired. It is impossible for our teachers to check if you did the task in the allocated time, if you used a dictionary, asked someone for help, or copy pasted from the Internet. All these things will affect your score. You are the only one who knows under which conditions you did the speaking, so you know much better how to interpret the results. We just don’t want to make you feel over confident when you look at the score and during the exam, when under a lot of stress, you expect to score the same.