i bet most mainstream car shows have never even heard of the word 'detail'. detailing is still fairly uncommon, unless your an enthusiast. shows like fifth gear are generally watched by people that like cars, not paint enthusiasts...so to try and keep it simple they incorporated the most common cleaning practices that joe public use...i.i car wash, and the local polish hand car wash
In this case I would agree with you as 'Detailing' is very much new to the UK and slowly spreading BUT...
The test was conducted by a rather well known detailer who is a master at his work and should have maybe tried to encourage 5th Gear a little to do a 4th test. Maybe he did I don't know what he tried but the fact is they went to the effort of correcting the paint at least then show the viewers that this can be looked after and it's not just a waisted effort.
Lee.