Maybe the acknowledgments gives a hint?
ACKNOWLEDGMENTS We would like to thank Kelly Idouchi, Manya Sleeper, James T. Graves, and Celine Berger for their contributions to this project. Similarly, we thank Chris Hoofnagle, Daniel Solove, and the attendees of the 2014 Privacy Law Scholars Conference (PLSC) for valuable feedback on an earlier version of this work.
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.