This trial is before Felix, who is corrupt and more interested in keeping the peace than in doing what is right. Paul is accused of causing riots, because Felix would be most interested in preventing any kind of uprising among the people. Paul simply tells the truth. Felix knows Paul is not guilty of breaking any law, but holds him without a conviction for two years in hopes of a bribe.
Even in a life-threatening situation, Paul relies solely on telling the truth. His accusers are taking threads of truth and spinning them into accusations that are clearly untrue. Paul even sees a legal trial as an opportunity to encourage people to consider Jesus. When most would be tempted to be defensive, Paul focuses on Jesus. How would you have reacted in this situation?