My understanding of the story was that he was not going to be able to pass the bar because of his plans to try and get out of his debt by ways other than paying it back, even though he assumed he would pass the bar? Might be wrong, it was a bit hard to dig through the outraged writing.

But he can do other things that will help him pay of his debt until he passes the bar and then work as a lawyer.

Just because you go for school for something doesn't mean your guaranteed a job doing just that. You go to school to learn something. Usually you use that knowledge to advance your career (or start one). However, it's unfair to demand that just because you went to school to become a lawyer (or doctor, or whatever) that people must hire you into that position.

Unless you were coerced or the contract came into being in some other illegitimate way, you certainly have a moral obligation to fulfill any promise you make, contract or otherwise.

<Quick moral theory> To be moral, an action must preserve agency of those involved. When any action is performed, a reciprocal standard of action is established. (When I do something, I am willing that it is ok for you to do it to me.) If the action in question strips another person of their moral agency, the actor initiating the action is also accepting that it is permissible to be stripped of their own agency. This is where the contradiction exists. If we authorize the removal of anothers agency, then we are authorizing the removal of our own agency as well, and thus our ability to determine morality.

Cliffs Notes: If you screw someone over, you're authorizing others to screw you over. This perverts your sense of morality and you are no longer sufficiently able to decide morality.