The Jailer had been converted overnight. He was still an officer of the court. One of the things that Paul and Silas were doing is validating their bound wounds, for the Jailer had bound them. They were giving their power (as Romans) to the church (who, generally, were not). This is the correct use of power. For others.
35 When it was daylight, the magistrates sent their officers to the jailer with the order: “Release those men.” 36 The jailer told Paul, “The magistrates have ordered that you and Silas be released. Now you can leave. Go in peace.”Acts 16:35-40, ESV
37 But Paul said to the officers: “They beat us publicly without a trial, even though we are Roman citizens, and threw us into prison. And now do they want to get rid of us quietly? No! Let them come themselves and escort us out.”
38 The officers reported this to the magistrates, and when they heard that Paul and Silas were Roman citizens, they were alarmed. 39 They came to appease them and escorted them from the prison, requesting them to leave the city. 40 After Paul and Silas came out of the prison, they went to Lydia’s house, where they met with the brothers and sisters and encouraged them. Then they left.