I was looking to confirm or deny that statement and came across a fun detour in the form of an article entitled "What's So Special About American Law?". It doesn't address the point about spirit vs. detail at all, but is an amusing and informative read.
> As I said, this fact seems to me a deep and fundamental point of difference. The American legal system, to a greater extent than any other Western legal system, encourages the direct injection of democratic values into the legal process. Our legal system, like our society, places great emphasis on the value of equality. We do not fully trust professional elites.
https://scholarship.law.upenn.edu/cgi/viewcontent.cgi?articl...