Public post-publication commentary is one route through which concerns about published research may be raised. PubPeer is a website for public post-publication comments concerning matters such as image presentation, figure consistency, statistical analysis, methodology, data reporting and interpretation. Published studies and formal retraction notices show that concerns raised after publication have, in some cases, preceded corrections, retractions or further journal investigation; these outcomes do not establish the accuracy of every comment, validate the website, or demonstrate the adequacy of its governance arrangements. When public comments are circulated to journals, institutions, funders, collaborators or employers, they may acquire consequences before the underlying concern has been independently assessed. This perspective critically examines the due-process implications of that transition, including evidentiary status, anonymity, expertise, high-volume commenting, moderation, reputational language, external amplification, persistent online visibility and institutional reliance. It argues that public comments should be treated as alerts requiring independent assessment, not as findings of misconduct or evidence in themselves. The article distinguishes documented observations, hypotheses for future empirical investigation and normative policy proposals. It does not infer the motives, competence, coordination, funding, institutional support or production methods of any commenter. A typology of comment types, a journal workflow and governance proposals are presented. The article does not confer endorsement, legitimacy or institutional authority on any platform. Its purpose is to identify safeguards required when comments hosted by a privately governed website become editorially, institutionally or reputationally consequential.