Martyn, I was never shown a form 5050? The circumstances were really as described, he was very polite and courteous and he noted the visit cards I had received and looked through the list of people I was carrying (and making notes) who were attending a function I was moderating at the evening before (and the reason for my being in London).
I was dressed for comfort traveling Y with Swiss out of LCY with a carry-on bag containing my suit and tie and a laptop bag I use as a briefcase. My cash, ID and credit cards were in my top shirt pocket, so out of sight but certainly not hidden.
I had no problem with being stopped, and I understand in today’s day and age it is often necessary, it’s just that I was within the law and unless he suspected (or discovered) I was carrying more than 10K I should not have been subjected to such treatment.
I appreciate your comments about technology working for you rather than the other way round, and I do try and achieve that. And when it works it’s great. Trouble is, sometimes it does not, and I like to think I’m then prepared.