These are case examples straight from NRMPs website. Basically it will depend on whether or not the applicant outright lied about something.
http://www.nrmp.org/res_match/policies/case.html
IV. Waiver Denied - Program
Description
After the 2005 Main Residency Match, the Pathology program at National Medical Center wrote to the NRMP, requesting a waiver of its match commitment to Dr. Baker. After Match Day, the program director obtained information about Dr. Baker's prior residency training, and he no longer felt comfortable offering him a position. The NRMP initiated a waiver review and learned that Dr. Baker had not omitted information about his prior residency training on his current residency application. Moreover, the new information obtained by the program after Match Day had been available prior to the rank order list deadline, when the program could have deleted the applicant's name from its rank order list. The NRMP denied the Pathology program's request for a waiver.
Policy
Section 5.1 of the Match Participation Agreement for Applicants and Programs states that the listing of an applicant by a program on its certified rank order list or of a program by an applicant on the applicant's certified rank order list establishes a binding commitment to offer or to accept an appointment if a match results. Failure to honor that commitment is a material breach of the Agreement and may result in penalties to the program or applicant.
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VIOLATION:
I. Violation - Applicants
Description
In the 2005 Main Residency Match, Dr. Scarlet O'Hara matched to the Family Practice program at American General Hospital. After the Match, the program informed the NRMP that Dr. O'Hara had forged her letters of recommendation. The NRMP initiated a violation investigation, collected information from relevant parties including the individuals who purportedly had signed the letters of recommendation, and determined that Dr. O'Hara had forged the letters. The NRMP permanently identified Dr. O'Hara as a match violator in the NRMP's Registration, Ranking and Results (R3) System, permanently barred her from participation in future NRMP matches, and sent a copy of the Final Report to the American Board of Medical Specialties and the Federation of State Medical Boards.
Policy:
Section 4.3 of the Match Participation Agreement for Applicants and Programs states that applicants are responsible for the completeness and accuracy of the information provided to programs, and programs are expected to provide complete and accurate information to interviewees. If the NRMP receives credible evidence that the applicant or program has violated the terms of the Agreement, the NRMP is authorized to take appropriate action.
Section 7.2 outlines for applicants and programs the consequences of a confirmed material violation of the Agreement. Applicants may be barred from subsequent NRMP matches and/or identified as a match violator to participating programs for up to three years or permanently, as determined by the NRMP.
