Regarding the year of CS courses, many schools require that applicant report all undergraduate and graduate level coursework regardless of whether the applicant received a degree.
For these schools, failure to report an entire year of coursework, especially when the student intentionally omits the coursework to conceal it from the school, seems a pretty clear ethics violation.
Making up a story to conceal the true nature of the coursework does not sound like an ethical best practice either. As is often the case, an attempted coverup might lead to far more damage than stating the truth upfront.
Penn/Wharton:
Transcripts of all academic work completed at the baccalaureate/undergraduate level and beyond, whether or not for credit or a degree, are required. Grades or marks may be self-reported on our online transcript template, with official documents required upon admissions and matriculation.