They could try to say that but I doubt people would believe it.

Who throws away their own code particularly when it’s not junky commercial code but code their heart and soul was behind on a non-profit project? I keep my old code around if anything just to be able to search it to re-teach myself coding and design tips I forgot about. This code backs their research which they may need to refer to when a prospective employer asks for detail on how they executed the study.