Peer review is never intended to be an independent audit of the data for any journal. Reviewers check the methodology, look for obvious mistakes or oversights,

Peer review is never intended to be an independent audit of the data for any journal. Reviewers check the methodology, look for obvious mistakes or oversights, provide suggestions for clarification or improvement in the text and for high-demand journals, weigh in on their opinion of the importance of the study. All of the feedback is based on the paper itself, so outright fraud usually is not caught at this stage unless the malicious author is exceptionally sloppy. It is later when other scientists start working to replicate or expand on the study that they request access to the data, and dig into the details. This is when most instances of scientific misconduct are found, and this paper is no exception. In science, publication is the start of the peer review process, not the end.