There are countless posts by people which lost all or some of their aUEC because they had some cargo and lost it all when the game crashed. This shows that CIG's approach on this matter (as on may others) is wrong. The cargo should work like this: once a purchase is registered (and aUEC subtracted from an account), cargo should be persistent (it should not be deleted, for any reason) unless it is sold. The game knows you no longer have those aUEC. It should also know you have that cargo.