One: The paladin don't need to hava a judge to decide that kidnapping is evil and should be punished. Death penalty is allowed.
Second: He should protect the innocent and helpless. By just running in that camp their safety is in danger. So he decided that a little bit sneakyness should help to safe innocent. Nopt a bed call. When the battle was over he showed mercy. Pretty good and honorble!
Do not punish you paladin for this. He did the right thing.