I assume you are referring to Tony S who I believe was quite active on some of the American forumsI do believe a dearly departed member did a full write up on the AFDD as it is an adopted Americanism IIRC from his explanation, introduced over there due to the lack of real testing being carried out and damn near pointless over here?
With regard to testing I think the UK does more testing than most countries, a few years ago I was over in Tenerife visiting a mate of mine who was renting a property out there, there was an electrical issue in the kitchen and the rental agent sent a local spark round to sort it and when I mentioned about testing the RCD he had never heard of an RCD tester, his only test equipment was a clampmeter / voltmeter