Your squadron SARMS folks should review each and every 781 that is filed. The review is pretty in-depth. For example, if you logged NVG time, but no associated night time, that should be caught. If you logged an instrument approach, you have to log some sort of instrument time or simulated instrument time. The takeoffs/landings will all equal up on the review as well.
The 'A' code on the orders does not dictate who is in the seat, it is only used for designating who is in command. The 'A' code can stand the entire time, not get in the seat and only log other time, but all the times, primary, secondary and other time all have to add up correctly.
The orders, 781's and review sheets are kept by the SARMS shop, I believe they are kept for some ridiculous amount of time, like 35 years or something.