The only reason beer is ever refrigerated is to sell it to people who want to drink it cold right away after purchase. The dates are always /best before/ dates on beer.

So IIUC, the grocer could have legally sold me the beer. In principle, a grocer could care about quality and decide not to sell anything past the /best before/ date.. Though I am skeptical that that would happen. The impression I got was that the staff at the grocery store did not even think about what kind of date it was.. just saw the date had passed and thus would not sell it.

So I have to wonder what happened to the clip of beer. The sensible thing for them to do is to put a -50% sticker on it, as they do with other beers that are just slow to move. I hope they did not pour it down a drain.