The bottles have identifiable corks when viewed under UV light. Some of the highest priced, pedigreed wines from some of the greatest vineyards in the world (Domaine Romanee Conti). You just can't walk into a store or call an auction house with those wines. The thieves must have known enough to know their value but not enough to know they would be traceable and vary hard to sell. Great restaurant, too.
I think the police got lucky with this one because the wine was actually returned anonymously by the buyer, whom the police deemed an "unsuspecting buyer." If that buyer didn't return the wine and kept it for himself, then I don't see how it could ever be recovered, even with the tricked out corks. Here's what I read about it:
In mid-January, less than a month after the French Laundry’s wine went missing, Brian Walker, a lawyer in Greensboro, N.C., called the Napa County Sheriff’s office and told them he had an anonymous client who knew where to find it. According to Walker, his client had purchased the wine from a broker he’d worked with before, only to find out from news articles that it had been stolen from the French Laundry. “I do know how they came to possess the wine,” Walker says. “But I can’t say what that is.” Four deputies flew from Napa to North Carolina and found all but four bottles of the French Laundry’s wine sitting in Walker’s law office. Walker says he doesn’t know what happened to the other four; his client never had them and assumes they’ve already been drunk.
This is from a pretty cool article talking about how authorities track down stolen and counterfeit wine. It also talks about a $650,000 wine heist in Seattle, whom the perpetrators are serving 14 years in prison for. For those interested:
http://www.bloomberg.com/graphics/2015-wine-detective-french-laundry-heist/
