FlexResponse Action Failed [Sharepoint Quarantine] failed with message: Could not quarantine file: ::faultcode => soap:Server::faultstring => Server was unable to process request. ---> Copy move operation failed ---> A list, survey, discussion board, or document library with the specified title already exists in this Web site. Please choose another title. ---> A list, survey, discussion board, or document library with the specified title already exists in this Web site. Please choose another title.::detail =>
SharePoint 2013 treats hyphens (the '-' character) as a word brake character. Here is the Microsoft development support case link:
SharePoint creates the file the first time properly. Then the file gets indexed. The indexing process seems to use a text processor to originate entries. This way the index would contain text with hyphens('-') replaced by path-separating slashes: '/'.
Another MSDN tech discussion confirms this: