Steps to ensure the test results are infallible and
foolcrpg-player-proof:
1. Take a pic of the inventory of the guy doing the raid before it is initiated, i.e. to prove he has absolutely nothing beforehand
2. Put awkward amounts of gear* unable to be purchased in the fief being raided, to prove it wasn't simply purchased immediately afterwards
3. Take a pic of the fief's inventory right before the raid
3.5 Optional step, take a picture of each inventory during the raid, after the reinforcement time has passed (if it is possible to prove that the battle is taking place while looking at the inventory/info tab, I have no idea)
4. Take pics of both the inventories afterwards, and the automatically generated post-battle messages, then compare results
*The amount in the fief should be fairly low, like 1 body armor, 1 axe, 2 pairs of boots, 3 gloves, and 1 practice shield. This way the profit from the duping is minimal, and it is fairly obvious that this gear didn't come from a prior attack or anything since no one would arm an entire fief with a single piece of armor, etc.
Even the conspiracy theorists, autists, retards and furries of this crpg community alike will be unable to refute the evidence if those steps are taken.
In b4 "Lel photoshopped" comments.