Flamm's comment about plagiarism appeared in a journal. InsideHigherEd discussed issues with book reviews in journals alleging plagiarism:
...journal editors are not only called upon to consider allegations about work they have published, but allegations that come in the form of book reviews of material published elsewhere.
“When accusations emerge before publication, for example during peer review of a manuscript, journals are in a position to handle the matter informally, either by rejecting the manuscript outright or by asking for changes,” the report says, noting (without offering an opinion of whether this is appropriate) that some journals just reject such pieces. “More serious are accusations that emerge during preparation of a book review, which anecdotal evidence suggests to be a frequent way that plagiarism charges come to the attention of journal editors. A journal that publishes a review containing such a charge risks involving itself in ensuing legal wrangles, including countercharges of defamation, which from the courts’ perspective is a serious matter indeed.”
One approach being used, the report says, is for journals receiving plagiarism allegations to submit them to an outside panel for review. One publication (not named in the study) has used that approach twice, and as a result in one case ran a review with a plagiarism accusation in it, and the accused author publishing a reply (acknowledging a problem but denying intent). In the other case, the outside review “in effected exonerated the accused author,” the report says.