In one of the links above, maybe the source story, there's a woeful tale of a bottle of wine valued at $100s of $1000s, and the would-be seller accidentally knocked it over onto the floor. Gone. Another problem that started to get larger during the uptick in baby boomer wine collecting was fakes.
OTOH, the head of the Rothschild family recounted (on 60 minutes, maybe?) how he'd been dining, in Scotland of all places, and ordered the house wine, and one sip, it was the best wine he'd ever tasted. What is this wine? Just our house wine. It was a 200 or so year old Rothschild, apparently this was a posh place.
I worked for a wine importer in NYC during my college years. They bought a recently discovered wine cellar that had four or five stories going down into the bedrock of the island not too far from Columbus Circle. The temperature was constant year around. The company used it for a warehouse for their wine and liquors.
Apparently the original owners had also been smugglers because there was also a tunnel that went down to the Hudson river. Anyway at the very bottom story where you had to climb down a ladder several large bottles of port ??? were found all covered with dust from the centuries. I dont know if they ever sold them or opened them.