Just relax yourself. There is no racism here and lets not add to the distraction by trying to make it UK v USA.
As Fara just highlighted to you the process of eminent good sense and just to add some clarity for UK events. Fly-ins UK style are not the mass Oshkosh or Sun 'n Fun type meetings in the main, simply because we are a tiny little island. A fly in for us is a mere gathering of like minded individuals and there are no pleasure flying just owner/drivers if you like landing, having a natter and a cup of tea and going home at the end of the day. In that context there is little to check because not much happens.
If however you go to a bigger event, for example the LAA (light aircraft association) fly in and then offer pleasure flights then you will sign to agree to T&C's that include your aircraft is all that it needs to be.
I would also draw your attention to the CAA "ginfo" site (link here)
https://siteapps.caa.co.uk/g-info/
If you visit that site anyone can instantly check the validity of a variety of metrics on the aircraft. Instantly. Which includes the permit validity period and that it is insured.
I don't think you are on anyones side John but you have started to become emotive with the suggestion of vendetta! I mean to even suggest that when I am just making a valid critique on a woeful lack of airmanship is the exact point I'm making.
Look its an opinion and I get you are being the nice guy because you actually deal with the individuals and so on but in playing things down, in suggesting its a one off, in suggesting that the paperwork makes no difference then don't you see that sends a message? You are playing the whole thing down and it was a woeful piece of airmanship on all sides.
Your problem is instead of just saying yes this shouldn't have happened and we will look at ways to ensure similar doesn't happen again, you lash out at the person spit balling the obvious snag and claim there is now a vendetta against the pilot. Are you literally insane? I don't know the guy, I have little likelihood of meeting the guy, I've no real interest in him, the aircraft, the aircrafts owner. I'm just saying "hey all these things that kill you... these are the holes in the cheese that can line up.."