I don't know - I think all legal systems use precedents to a certain extent - they're just extremely formalized in America and Britain. Sorry but I'm not familiar enough with their system to reply with confidence but I would say that if a high court in a country rules a certain way, even if that isn't binding to future rulings, it will cause people to adjust their behavior to avoid falling into a trap that's been clearly called out already.

Uh, also, IANAL.