Re: "Britain's FBI"
You would think the existence of a separate and distinct legal system and practice here in Scotland in their own polity would make them wise to the possibility. Let alone travel in modern Europe where there's little except a sign to indicate a border now.
But then we still get people from south of the border surprised at the fact. They think that our Sheriffs and Procurator Fiscals are just quaint names and the law is the same.
The Welsh, since Devolution, have built up a sufficient corpus of different Welsh law that they are thinking about separating out their legal system from England's for the first time since the 15thC.
And I haven't even mentioned the Channel Islands, Man and NI.
So really there is no excuse.