On reading the comments below the original article and also the discussion here by a guy who tried to recreate Marcott's results, it sounds like neither the original data nor Marcott's revised data can be trusted. Those big upward and downward spikes near 2000 could be artifacts.
As for prosecutable fraud, IANAL but I think we will have to settle for Marcott's reputation taking a hit.
Was his intent to deceive? Did he gain from his deception? It seems that it should be prosecutable:
Fraud is generally defined in the law as an intentional misrepresentation of material existing fact made by one person to another with knowledge of its falsity and for the purpose of inducing the other person to act, and upon which the other person relies with resulting injury or damage. Fraud may also be made by an omission or purposeful failure to state material facts, which nondisclosure makes other statements misleading.
To constitute fraud, a misrepresentation or omission must also relate to an ‘existing fact’, not a promise to do something in the future, unless the person who made the promise did so without any present intent to perform it or with a positive intent not to perform it. Promises to do something in the future or a mere expression of opinion cannot be the basis of a claim of fraud unless the person stating the opinion has exclusive or superior knowledge of existing facts which are inconsistent with such opinion. The false statement or omission must be material, meaning that it was significant to the decision to be made.
Sometimes, it must be shown that the plaintiff’s reliance was justifiable, and that upon reasonable inquiry would not have discovered the truth of the matter. For injury or damage to be the result of fraud, it must be shown that, except for the fraud, the injury or damage would not have occurred.
To constitute fraud the misrepresentation or omission must be made knowingly and intentionally, not as a result of mistake or accident, or in negligent disregard of its truth or falsity. Also, the plaintiff must prove that the defendant intended for the plaintiff to rely upon the misrepresentation and/or omission; that the plaintiff did in fact rely upon the misrepresentation and/or omission; and that the plaintiff suffered injury or damage as a result of the fraud. Damages may include punitive damages as a punishment or public example due to the malicious nature of the fraud.
There are many state and federal laws to regulate fraud in numerous areas. Some of the areas most heavily litigated include consumer fraud, corporate fraud, and insurance fraud.