> The real translator touch comes about when their is some nuance to the language.

And as we all know legal language is famous for having no nuance whatsoever, there are no opaque technical terms with hundreds of years of history behind their usage, there is no difference between the legal systems of different countries, and there is no possible difference in case law or the practicalities of legal enforcement. /sarcasm

What is clear to me that in a situation like this neither AI translation nor human translation is sufficient. What the imagined American signing an important legal document in the Czech Republic needs is a lawyer practicing in the Czech Republic who speaks a language the imagined American also speaks.