In 2020 serious concerns were raised by members of the scientific community regarding some of the conclusions reached by this publication in Nature. The four of us were contacted by the TU Delft to provide advice on this issue. The authors provided us access to unpublished data available to them prior to publication. This public version of our report focuses on the scientific methodology and interpretation, in light of the data and the theoretical background available to the authors at the time of submission. In particular, we aim to provide a snapshot of that timeframe, and pay minimal attention to more recent theoretical developments that may influence the authors’ current thinking. We also do not consider subsequent experimental findings, except inasmuch as they shed light on the thinking prior to publication. The conclusions and opinions stated are those of the authors and not of their institutions.