"If they hadn’t visited Thailand in 2002, they wouldn't be living there now."

If they hadn’t visited Thailand in 2002, they wouldn’t be living there now.

Here why the past perfect form was used at a specific time?

I’ve learned that the perfect form shouldn’t be used at a specific time. Here the sentence invovles "in 2002", so is the tense correct? I’ve never seen this.

[Tests of conditionals:if]
[1]: https://dictionary.cambridge.org/zhs/plus/quiz/%E8%AF%AD%E6%B3%95/conditionals-2