As I see it still, both are using the decision of the court to their own favour only when it falls in their favour, and ignoring it the rest of the time:
Protagoras
WINS: Student has to pay him by order of the court.
LOSES: Student has to pay him by his original agreement.
Student
WINS: Student doesn't have to pay by order of the court.
LOSES: Student doesn't have to pay by the original agreement.
So in both situations, you could choose to follow the order of the court, or the original agreement. However, the court is meant to resolve disputes, and has the power to override any previous agreements, ruling in favour of one of the parties. So with this in mind, the situation should be:
Protagoras
WINS: Student has to pay him by order of the court.
LOSES: Student doesn't have to pay him (by order of the court).
Student
WINS: Student doesn't have to pay by order of the court.
LOSES: Student has to pay (by order of the court).
Protagoras
WINS: Student has to pay him by order of the court.
LOSES: Student has to pay him by his original agreement.
Student
WINS: Student doesn't have to pay by order of the court.
LOSES: Student doesn't have to pay by the original agreement.
So in both situations, you could choose to follow the order of the court, or the original agreement. However, the court is meant to resolve disputes, and has the power to override any previous agreements, ruling in favour of one of the parties. So with this in mind, the situation should be:
Protagoras
WINS: Student has to pay him by order of the court.
LOSES: Student doesn't have to pay him (by order of the court).
Student
WINS: Student doesn't have to pay by order of the court.
LOSES: Student has to pay (by order of the court).