Semantics aside, the presumed issues are: 1. Is shnaim mikra a chiyuv? and 2. Assuming it is, does noncompliance with the chiyuv pass the mysterious threshold of “aveirah”?
The first issue is pretty much straightforward. Despite all the cute diyukim above, the sh”a paskens that it is a chiyuv. As far as the second question, it is nearly impossible to answer without further detail, and is mostly a question of assumptions and semantics.