Unlike most search engines on the market, when no more results can be found that contain all of your query terms, Gigablast will start to return results that contain most of your query terms. We call this feature Super Recall.
Gigablast will let you know when the results do not contain all of your query terms by displaying a large blue bar like this one:
The results below may not have all your query terms. [Info]
Super Recall saves you time by returning results for queries for which other search engines would display the dreaded "No Results Found" page. Super Recall is especially useful for query misspellings and smaller indexes, like individual site or corporate indexes.
To force Gigablast to just return pages that have all query terms you can use the interface on the advanced search page or you can prepend each query term or phrase with a '+' sign as illustrated on the help page.