When for example you have english and french enabled you will have 2 indexes for them:
content-node-en
content-node-fr
While initially node without translation is saved into either one of those indexes, then changing the language on the node, will save the entry to correct index but leave the old entry intact.
Comments
Comment #2
hkirsman commentedI added orphanCleanup() function to my custon module in the index() method.