Indeed, I can't remember for sure but I think that it is two random travellers to the US every day on BA flights, and by rotation that includes a CWLCY every few days. From my understanding, the slow security people was indeed not unexpected and the ground staff were quite apologetic/embarrassed about it! In my case, I had actually showed up quite early because of the issue with OLCI (interestingly, like the OP I was travelling with my partner whose BP was obtained without issue online). To give a sense of the time it took, I think I was at the airport 1h30 before the flight because of that, and by the time I joined her, all the other passengers were on board and she was the only one waiting for me in the gate lounge!