Run this a few times and observe how matched_filters is randomly present in the results.

gistfile1.sh

curl -XDELETE "http://localhost:9200/bug"

curl -XPOST "http://localhost:9200/bug/article/" -d '{"content": "Lorem ipsum dolor sit amet"}'
curl -XPOST "http://localhost:9200/bug/article/" -d '{"content": "consectetur adipisicing elit"}'

curl -XPOST "http://localhost:9200/bug/_refresh"

curl -XPOST "http://localhost:9200/bug/article/_search?pretty=true" -d '
{
   "query":{
      "bool":{
         "minimum_should_match": 1,
         "should":[
            {
                "query_string":{
                   "query": "dolor",
                   "_name": "dolor"
                }
            },
            {
                "query_string":{
                   "query": "elit",
                   "_name": "elit"
                }
            }
         ]
      }
   }
}
'