Can spud avoid his obligations under the contract because of this emergency job? yes, since he has an offer where he can make more money. yes, emergencies allow cancellation of the contract in all cases. no, an emergency never affords relief under a contract. no, since the emergency did not make performance impossible, he must finish the job.
Spud has entered into the contract already and he has to perform his obligations despite the emergency he has at hand. If the emergency he has is a type that will make the performance of the remaining job impossible it would have been understandable, but since the emergency is another job that he just secure, he is expected to finish the job he has at hand and satisfy the conditions of the contract before he start another job.
Spud cannot avoid his obligations under the contract since the emergency did not make the performance impossible.
Once he has signed the contract, he is bound to complete the contract. There is no such emergency relief in contracts.
If he was expecting some other better job, he should not have signed the contract. but once he has undergone the contract terms and conditions, he is legally bound to make it happen.
Besides the legality, it is his moral and ethical responsibility as well to finish the job he has signed for.