This is an EU directive and not a law. Yes, there's a difference:
Directive (European Union) - Wikipedia, the free encyclopedia).
A directive is not intended to apply directly in member states. The idea is that member states pass national laws to put it into effect. This "Law" has not been implemented in the UK.
I suspect Tesco gave in just to avoid the hassle (time and costs) of going to court as most large retailers would.