With the sheer quantity of people booking BA flights, there will be multiple times a day where you click on 'book' to find the price increase as someone else has literally *just* nabbed the last O or Q class seats or whatever, so it prices what is available.
So the disclaimer is relevant even if the average BA traveller will never see this.
Obviously not happening in this case, which is an IT issue.
Can you not book 2 x one way fares and pay what's stated? What am I missing?
Also "Drinks and M&S food available to buy on flights to/from London Heathrow and London Gatwick" - so these DUB-IBZ flights will have free booze?