Facts and opinions (at GCSE level) are to do with how information is presented; you can't check if information is true or false in an exam. Compare the two statements below:
What's the difference in how these sentences are presenting information? The first one attempts to present the information as a fact, however the second one attempts to present the information as an opinion instead (as it focuses more on the author's thoughts and feelings).
When you talk about facts and opinions in a text, you should talk about how the information is presented. Use phrases like, "The author presents the fans' disappointment as a fact in the sentence..." or "The author presents the fans' disappointment as an opinion in the sentence..." This is much better than saying, "The author uses a fact." as we don't actually 100% know if it is a fact or not.