What's an instance where sociolinguistic factors greatly impacted the outcome of your linguistic research?

As a translator I encounter the need to conduct sociolinguistic research on a regular basis, especially when it comes to research of proper terminology. One prominent example where sociolinguistic factors impacted the outcome of my linguistic research was a project where I had to translate an asylum statement of the applicant. To begin with, as we all know, while asylum statement may at first seem like a literary translation where a person tells a story, the facts of the statement must still be translated with outmost veracity and precision. Nevertheless, throughout the story we might find special terms that particularly relate to things like cultural environment where the asylee comes from, geographical location or even social class (as they still exist in some cultures). So, when being encountered with these terms, it is obvious that we need to dig deeper than just a simple dictionary in order to find the meaning, explanation and cultural context in which this term is used. To illustrate an example, let's pretend that the asylee describes an incident during which some offender confronts him and uses some colloquial term that is particularly very common in his culture, but at the same time may sound unknown or even incomprehensible to immigration services officer who will be reviewing his case. So, in this particular example, the translator's job is not only to find the correct equivalent but also to transcreate it in a way that it will also be clear and comprehensible to the target reader (asylum officer). And for that to happen, translator may need to consult with certain thematic glossaries and historical books in order to be able to explain what that colloquial term means.