The EU laws are sometimes not implemented exactly the same way in all the countries inside the union, so I'm not going to tell you that this is wrong in relation to UK - I honestly don't know.
However, for my country, Denmark, this is not the case. You are allowed to open the product and examine it just like if you were in a store. If you can return the product in the same condition as it arrived, you're good. If you take the laptop out of the box, it's still in the same condition.
The line is drawn when you take it to use. So if you set it up in your own name and take it for a test drive in geekbench or whatever, you're across the line. You still have the right to return the product at this point, but you have to pay for the difference between the original value and the value after your use.