"Do you remember that Christmas where we didn't get any toys?"
Why would the speaker be using "where" in the sentence? Should I use "where or when" when refering to experiences,incidents or situations?
"I've been in a situation where/when? I was shortchanged."
Where can also be used after some specific nouns such as situation, point and stage, e.g.:
Eventually I reached a stage where I began to enjoy my work.
He found himself in a situation where he was unable to pay off his debts.
When can be used as a relative adverb in a relative clause after the word time or other nouns which denote periods of time such as year, day, summer, etc.
e.g.:
I remember the day when I first met her.
Wasn’t that the summer when we took the boys camping?
Yes.
I think it should be "when".
Christmas is indeed a time of year and the fact that the original says "...that Christmas where we didn't get any toys..." shows that they are talking about Christmas Day, the day when presents are given and received.
However, you will hear "where" and "when" used a lot in these situations by native speakers, without much thought to which one is correct.