Sounds right.

Naturally, there is no functional means to know when "indexing" actually occurred, in LA or otherwise.  

There is no separate stamp or indicator given to a document as to when it is actually indexed.  

This is typically "Metadata" in a computer system, akin to all that data held in a computer as it pertains to a photograph in JPEG format.  Few of us bother to look at it but it is there and subject to discovery if such matters are sought in an action like this.