Further, why would Von Braun be an expert on lunar meteorites? He was an engineer, not a geologist. Your scenario doesn't make sense, and is not supported by evidence.
Nobody even knew there were such things as lunar meteorites in the Austral summer of 1966/67 which is when WvB was in the Antarctic. A few Antarctic meteorites were known at this time - the first being found on Mawson's expedition in 1912, but serious collecting did not start until the Austral summer of 1969/70.
WvB was interested primarily in the management and logistics sides of the operation, not the science. He was a manager after all. As far as I know the only field trip he did was to the dry valleys (not a good place for meteorites), the rest of the time he was at the stations. WvB's visit was reported in the media (National Geographic, Popular Mechanics ran articles), which is rather odd for a mission supposedly to secretly collect rocks.
Then there is the little matter that the rocks of the Antarctic Dry Valleys bear little relation to lunar rocks. They include dolerite, granite, gneiss, sandstone, tillites, and conglomerate, even coals. No basalt, gabbro, anorthosite, norite, impact breccias, impact glasses, or anything else found in lunar samples. They are also only 180-500 million years old, unlike the lunar samples which are all 3.2-4.5 billion years old.
And of course the Dry Valley soils are not impregnated with solar wind gases, nor do the rocks show space weathering (micrometeorite pits, cosmic ray damage, high levels of cosmogenic isotopes, vacuum welding).
