If this blogger is indeed a FTer, I would be interested to see what he has to say about this. The fact that two threads have been started today suggests that the video has been viewed quite a lot and this particular point has caused a lot of people to sit up and take notice.

It is true that you can get different prices for the same BA flights by changing the POS, if that changes the inventory available to you. Two perfectly legitimate methods have been mentioned here already. But AFAIK you cannot do this by trying to manipulate ba.com because it will always sell you tickets for any specific itinerary in the same way regardless of where you are when you book and what country selection you make on the website.

There are some other airlines which will offer you different prices depending on which country version of their website they use. But the airlines that I have used whose websites work like this don't change the price depending on where you are; you just need to select a different country version.