You need to re-read what fraud is. While the OP might not have intended to work for the petitioning employer at the time the petition was approved, that is NOT fraud. Fraud would be if she never intended to work for the employer at all.
Actually marriage to a US citizen is pretty clear evidence that there is no fraudulent intent. She could have adjusted status without any difficulty on this basis, so there was no need to engage in fraud for an immigration benefit via the EB route and her course of action was an innocent mistake. The bona fide US citizen marriage and its longevity makes fraud almost impossible to prove.
TRC,
Let us delve into the simple for the purposes of illuminating this discussion with a diversion, because your response above necessitates that we do so. This is what fraud is defined as:
1 a : deceit, trickery; specifically : intentional perversion of truth in order to induce another to part with something of value or to surrender a legal right b : an act of deceiving or misrepresenting : trick
2 a : a person who is not what he or she pretends to be : impostor; also : one who defrauds : cheat b : one that is not what it seems or is represented to be
synonyms see deception, imposture
In the case the OP presented, he clearly gained something of value from the employer (greencard). The employer lost something of value, money and human capital (the OP as employee), and never gained anything as a result of the act of the OP (leaving to pursue BS). Moreover, if the OP has indicated to the employer that he intends to go to BS, do you think the employer would have spend resources to procure a GC for the OP? We all know the answer to that question.
I like your certainty that his marriage to a USC for a long time defuse the possibility that fraud was involved, what a confident man. Have you ever heard of people whose cases and LPR status were revoked after decades in this country? In almost 90% of those cases, fraud didn't require proof beyond reasonable doubt, but rather the simple fact that more than likely or not he did commit an act of deception, and gained something of value which shouldn't been given in the 1st place.
Anxious raise an important point regarding accepting a greencard after being laid-off, under what theory are you accepting it? TRC, please provide us some USCIS issued manual which condone such a behavior, because I am anxious to read about it...lol!!!
Under your theory, let take this example, a young couple recently married and one is an immigrant, wife files for the paperwork. Fast forward, interview is scheduled and attended, IO tells the couple, sorry, can't make a decision, you will receive something in the mail. Another fast forward, 3 months go by and no decision, wife has nuts attack, die due to allergy. What a tragedy!! Wife is buried and 2 months later, USCIS approves the case, I know you are asking, what is the approval date, two months after the wife has died. What is the husband supposed to do? Accept the GC and start over only for his balls to be busted when he naturalize or return it and indicate he's no longer entitled to the GC because the petitioner is deceased? I am all ears, TRC...will read your response, let me go and please my wife...lol!!! Oh....the husband also sue the offending party, which happens to be Cheesecake Factory, as the liable party for his wife's cause of dead, nuts in a mushroom soup and get $3million in settlement, what an unlucky man, wife is dead and he's a millionaire.