How would you diagnose a site like this? And I mean, it exclusively, only ever shows up after "Results for similar searches". It's not "end of results" per se - there could still be full 10 pages of results shown for the query but my site's listing will only show after "Results for similar searches" which in some cases could be on page 1. So it could actually be in a decent position #5 or #6 but only if there are just 3-4 "normal" results and the rest - "Results for similar searches".
In other words, it looks like it ranks fine within the "Results for similar searches" subset but nowhere in the normal results?
@g1smd: yes, it has content (at least pieces of it) that is a duplicate. The site makes heavy use of aggregation. Nothing nefarious: just adds a layer of service to publicly available information and I have seen the same bits and pieces used on 4-5 other sites out there (bits and pieces, not entire exact pages).
But to answer your question: usually there is neither exact duplicate nor a "shared bits" site anywhere on the SERP page, neither in "normal" results nor in "Results for similar searches". I've yet to find an efficient way to check ALL SERPs for that query but at least I can be sure there's no duplicate on the same page my site shows up at. I'm very sure there are no duplicates in "normal" results because usually there's only 3-4 to check, otherwise my site would just not show up at all.