Search API - weird issue, investigating further before bug report

[Jay]

Using the Python 2.7 runtime.

We have a search index that has some user information in it. One of these fields is a simple number field "total_points".  I just observed that one of our top players was not showing up in results. They should have been the number 2 player. 

I manually looked at the index using the admin console tool. It was sufficient for this purpose. Sure enough, the document representing that player was in there. And the total_points field had the correct value. I removed all the sorts from the query we are using when querying the index except for that total_points sort. The player still did not show up in the index. Just to try something, I "manually" re-indexed the player into the search  index through the api. And just like that, the player showed up again in the search results.

From what I can tell it is as if the document got "stale", it had not been updated in about a week, and was not returned by the search service - even though the sort was not on a field that had anything to do with time (although total_points does change of course, this player was so far out in front that they were still number 2 even after a week of no points). 

Has anyone else run across this sort of scenario? I wouldn't know how to reproduce it.

Thanks for any input.