User ABC has 40 posts.
User XYZ registered today and has 1 post, saying he's returned and cannot remember his old username.
User ABC is merged into User XYZ
User XYZ now shows 41 posts. Open model member card, and click integer in "Messages: 41" to search for user XYZ's message (eg. /search/member?user_id=47790 )
Search results only give the 1 posts created by user XYZ, not the 40 posts created by user ABC (now merged into XYZ).
Using ElasticSearch 1.3.4