Inadvertent duplicate publication of the same article a month apart in the same journal

This was an unfortunate situation where several checks and balances already in place at the journal failed during the peer review and production process leading to inadvertent duplication of a manuscript. Additionally, there were technical glitches, and the duplication of manuscript was missed by the authors, editors and journal staff as well. The duplicate articles were published a month apart. 

Although no situation was exactly alike, while reviewing previous COPE forum cases we realise that we can publish a “notice of duplicate publication” for both the papers and remove the article that was published later from the scientific record. To do so appropriately, we have a few questions about the process itself: 

Questions for the Forum

• Is this the most appropriate way forward to correct the scholarly record? 
• Is the notice of duplicate publication considered a correction because at least one article is also retracted/removed in the process? 
• Is it correct that the digital presence of the manuscript that is removed will only appear as a ‘tombstone’, showing the title/DOI/author byline and abstract?
• Should the DOIs of the two published articles be merged so that they resolve to the same location? 
• We are aware that the author may not fully understand the process and may have concerns. Does the Forum have any advice about how to handle this and whether it should be presented to them as a correction?