Suppose a piece of kit is Class II double insulated and doesn't need an earth wire (proper factory stuff with magic stickers & everything).
It's now placed inside a big tin can.
This tin can is placed temporarily in an environment that's full of high power electrics, ad hoc connections, extreme hazard for shock or falls from a height. The culture here (on paper at least) is that everything has to be carefully earthed and PAT tested before use, especially if it's foreign kit coming in from outside.
If you're wondering, it's stage lighting gear.
What's the situation here, both practically and legislatively? An argument can be made that a class II device that is safe without an earth doesn't (or does it?) become unsafe if it's inside a conductive metal outer housing. Despite this though, any sensible spark with responsibility for incoming kit will presumably see a metal housing and want to see an earth connection to it - they have neither time nor credible ability to open it up and demonstrate that the insides are safe without?
Thanks for any comments.