I’m not sure. It was at someone else’s place, and it’s a brown-bag group where everyone brings a bottle. But it was the eighth wine, so I’d guess it had been decanted for a while.
The problem was not that the wine was closed. It was pretty approachable. The problem was that it had no depth, structure or cabernet flavors. Pinot cherries aren’t going to morph into black currants and chocolate, and tannin won’t mysteriously emerge, with time in the decanter.