@Carl I agree that it's not common, but it does happen that an employer issues an incorrect W-2 and refuses to correct it. That's why the IRS has a form to deal with the situation. One of the reasons to file Form 4852 is "an employer or payer has issued an incorrect Form W-2." See "Purpose of form" in the instructions for Form 4852. Also see the following links on the IRS web site.
<a rel="nofollow" target="_blank" href="
http://www.irs.gov/taxtopics/tc154.html">http://www.irs.gov/taxtopics/tc154.html</a>
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/faqs/irs-procedures/w-2-additional-incorrect-lost-non-receipt-omitted/w-2-additi...>
If the IRS says that you can file Form 4852 for an incorrect W-2, it certainly cannot be considered fraudulent.
