I took a client to a fairly upscale restaurant in my area this week. This guy likes wine but is not a geek, so as we were both having seafood I ordered a lower end white burg. When the waiter poured it seemed OK initially, but after a few minutes I noticed the sherry-like flavor, and it began to quickly fall apart. I mentioned this to the waiter; the steward tasted it, immediately agreed with me and suggested that I make another choice on the basis that the rest of the case was also probably damaged. I did so, the new bottle was fine and that was the end of that.
But later I got to thinking: the cork was fine, and I did not notice any leakage or damage to the cap. What would cause this type of damage to happen? Heat seems the most likely, but are there other conditions that cause a wine to oxidise?