Look, I'm a H&S professional FWIW. I know anyone can be anything on the Internet, but that's what I do for a living. I deal with the contractors who remove this stuff, day in and day out as part of my job. I inspect their work. I inspect their equipment. I look at their working methods, systems, management, supervision standards, control methods, the lot. Its a highly regarded industry. If the work was done by a licensed contractor, it was very likely done to an extremely high standard.
A short description of what happens:
It will have been done inside a thick plastic enclosure, held under negative pressure to keep all fibres inside it. The AIB will have been removed in as large and intact a piece as possible to minimise the release of fibres from the asbestos board.
The workers will have undergone significant decontamination processes before leaving the enclosure at any timr. The waste will have been double bagged inside the enclosure and the outside decontaminated before being removed from the enclosure to be appropriately disposed of.
The area around the board will have been decontaminated and cleaned, then sealed to ensure any stray fibres cannot be released in future.
Then the whole enclosure will have been cleaned.
Only then is the analyst brought in. They are an independent company, and check the work, check for fibres in the work area carry out an air check, then run an air test and check for fibres under a microscope. If it passes, the enclosure is taken down. If it fails, the workers go back in to clean up and the analyst does the check from the beginning again.
It's a rigorous test.
However, please be aware that there are always asbestos fibres in the air, even when walking down the street and in new build houses, so you NEVER get an absolute zero result except in clean rooms in laboratories.
So be careful if you read the certificates, as they WILL show some fibres on the count. This is legal, and normal.