In papers in areas such as engineering and the physical sciences, figures, tables and formulae are the basic elements to communicate the authors' core ideas, workings and results. As a computational text-matching tool, CrossCheck cannot work on these non-textual elements to detect plagiarism. Consequently, when comparing engineering or physical sciences papers, CrossCheck may return a low similarity index even when plagiarism has in fact taken place. A case of demonstrated plagiarism involving engineering papers with a low similarity index is discussed, and editor's experiences and suggestions are given on how to tackle this problem. The case shows a lack of understanding of plagiarism by some authors or editors, and illustrates the difficulty of getting some editors and publishers to take appropriate action. Consequently, authors, journal editors, and reviewers, as well as research institutions all are duty-bound not only to recognize the differences between ethical and unethical behavior in order to protect a healthy research environment, and also to maintain consistent ethical publishing standards.