Semp if something happened before your own fixed recording period, which I suggested as 10 minutes to get the idea going, then you're out of luck. Can't provide for every eventuality, this is already way of pulling something back from the past as it is!
Chalenge, you should start an iTunes-a-like for ahf files thread, if you think that's a better solution.
Flushing data to file is usually a background task and more a question of altering the algorithm, there should be no increased processing overhead.
Boy, the cynicism! I don't get anything out of this myself you know. I just gave some thought to a feature the game doesn't currently have and presented it, for free, for the benefit the whole player base. It's in the Wishlist because there's no Suggestion Box.