The student's decision is a reflection of the ethical principle : Keeping promises and trustworthiness.
Keeping promises and trustworthiness: When a person makes truthful representations, provides correct information in order to set right certain misconceptions and makes every effort (both in letter and spirit) to keep his/her commitment, that person is trustworthy. Trustworthy persons do not justify their non-performance by citing legal or technical interpretations to support such behavior.