No and Yes
A jury can not rule on matters of law. Only on matters of fact. As it happens juries will occasionally forget this and try to change the law. This is called jury nullification. If it is obvious they were doing this a judge will usually set aside the jury verdict and issue a different judgment. If not, the case can be appealled. Remember that the winner in a jury trial is given the benefit of assuming all of the facts are true during appeal. This means only issues of law can be appealed.
