On our way into London - our first stop before going on to Dublin - we had company on our flight. See photo. Nice. But then Brit customs. It seems that the Italians and the Brits have this "virus": "let's-make-it-hard-on-the-tourists". So our flight landed in London on time exactly and we had 1 hour and 35 minutes to get from our arriving flight to Rollin's departing flight. He was - just barely - able to do it. I could not get there in time to see him off. Long walks. First, BA226 told us that because we were just changing planes we did not need to fill out a UK customs form. Fortunately, I stopped at an info desk and we found out to the contrary. Next a moderately long line for checking our cards and passports. Next, another line to check our boarding passes. Next a line to run biometrics on our faces. Next security. I was specifically told by one agent I did not need to take off my boots. When I got ready to be scanned they changed their minds. Next another line to get the biometrics photo of our faces confirmed. Everything is narrow so when a flight is de-planeing, all E-W foot traffic gets blocked with a sliding door until all passengers file by, and vice versa. I got caught in one of those holds 2x. Finally got to Rollin's departure gate. Boarding had just finished, he was not there, so I assume he was on board. I asked if I could fly on that flight: "No, this is an Are Mingus flight and we don't accept BA tickets" except this flight was booked as a BA flight. Now I have a 5 hour wait for my flight.
We have had a similar Brit customs experience going to London for the day from Paris last spring.