I recently received a peer review report from a journal. They rejected my paper for several reasons, the umbrella explanation is that my work is not suited for that journal. However, there was a comment in the peer reviewers' reports that effectively accuses me of plagiarism:
"It appears some of the formulas and cost method information is taken from a text that is not cited."
This is the only sentence in any of the peer review comments that mentions this. This reviewer does not seem to be accusing me of malicious intent, but likely thinks I forgot to add a citation. I do not think I did. I have looked through my paper to determine if they are correct. There are things I have not cited, but they seem to be common mathematical knowledge (an application of the definition of the expected value of a random variable, for example) or my own work with justifying arguments. I have requested more info from the editor to no avail. Is this something that should worry me? Should I be pushing for more details? Do I just ignore this and move on to the next submission?