Curious how rare some of the bottles are. I've read that the fine wine community is pretty knowledgeable and tight knit, so I wonder if trying to sell an ultra rare bottle would raise any red flags.
Hyper wealthy are also incredibly amoral and willing to purchase/trade in stolen goods. Just look at the art world - where do you think stolen paintings end up?
Wine is even easier - they can drink and dispose of it without anybody being the wiser.