IIRC the Chinese leak was regarding a somewhat modern but not quite top-of-the-line tank round (80s-90s maybe) featuring dimensions and/or characteristics. Information that would be pretty easy to use in order to calculate both how good that specific shell is, but also make it a lot easier to get a good estimate for more modern rounds developed afterwards. It was as you said largely overlooked and was quickly quited down. But there was actually one more not mentioned, a person brought in as an advisor/expert to help with developing German helicopters (unsure exactly what his merits were, have seen pilot mentioned but not sure on that) also provided the developer information that was later revealed to be classified. <br><br>I will also add that the developer kind of only have themselves to blame for these things happening in relation to their game. They have HEAVILY marketed the realism aspects of their game and make no changes to vehicles unless that change can be backed up with historical documents. They have also adopted an increasingly hostile "prove that we are wrong" tone whenever any aspect of their vehicles depictions are questioned and have started demanding more and more proof over the years before they make any changes. Anyone with half a brain would have seen these leaks coming as soon as they started introducing contemporary vehicles several years ago and yet here we are.