Oh, if it were a simple case of double exposure, I agree with you completely, and would have loved the opportunity to play the hand correctly.
However, this was a case where the dealer flipped the incorrect card, thus showing us his "down card," but not showing us his "up card." So technically, on average, this wouldn't harm any players, as you can well imagine -- the players are statistically ambivalent about which of the two cards is shown. I was hoping, though, that as a would-be ploppy, I could make the argument that I might now be making the wrong play -- i.e., that if his other card were showing, the statistically correct play might be completely different for me and the rest of the table. A superstitious player could certainly raise some "legitimate" issues, no?