So, you seem to have invited me to extend the query in my previous post,
Acts depicts Peter and other apostles persecuted for miracle working, not for the content of their speech. Nobody disputed that they did miracles and invoked Jesus when doing them, so there were no disputed facts for them to recant. Stephen was killed for an overt blapshemy about a question of Jewish religion, not for anything he taught about Jesus' life.
Stephen wasn't a witness anyway, so far as we know, but was at least a close associate in the Jerusalem ministry. Paul is neither a witness nor well placed in the Jerusalem ministry, a point of pride with him. He does endure the hardships and risks of the road, and has poor relations with various local authorities, but the actual subject of their quarrels is at best vague.
There's nobody getting killed in the canon for what they preach about Jesus' life, nor even much record of preaching what the preacher was a witness to.