I have booked a couple of rooms in a swanky overpriced-but-very-nice hotel for a weekend city break for a few of us sans enfants in a couple of weeks, something we've wanted to do for ages.
I managed to get the rate down from the original quote, they couldn't reduce the 2nd night but have reduced the rate for the 1st night quite a lot for us.
Some dizzy girl kept sending confirmations to my email for the wrong dates, then the wrong names, and other cock ups. Eventually she has sent what she says are the final confirmations and she hopes all the problems are sorted.
The final confirmations have the same cheaper rate for the 1st and 2nd nights, making the cost of the whole stay half of the original quote before we bargained it down.
Should we say nothing and turn up with these latest confirmations and pay the lower rate? (conscience is niggling that this poor dizzy girl will get a bollocking for the mistake)
Well.....I don't think it is the same as being given too much change in a shop iyswim. The prices of these things are always negotiable - no two people ever seem to pay the same price for a holiday for example...
On that basis you don't know for certain it's a mistake. So I don't think you would be very wrong for leaving it as it is. That's just my view.