Yet more attempted duplicate publication

A study submitted to a journal was sent out for external review. The reviewer pointed out that it was essentially a shorter version of a paper already published elsewhere. The authors had referenced this paper, but did not make clear that the submitted paper was simply a summary of the other published paper. Nor did they mention the other paper in the covering letter, or include a copy of it. One of the differences between the two papers was that the original study had 17 authors, while the paper listed only 10. The editor sent a stiff note to the authors saying that the journal regards this as poor publication practice. Should more be done?