How is it that HN accepted this, the link is an exact duplicate of http://news.ycombinator.com/item?id=205709 http://news.ycombinator.com/item?id=205709 ? I th

How is it that HN accepted this, the link is an exact duplicate of http://news.ycombinator.com/item?id=205709 http://news.ycombinator.com/item?id=205709 ? I thought there was a check for dup links...