A US based company selling a test abroad would be liable along with its directors. A doctor in the US or another country including the UK would be entitled to trust that these tests are clinically validated, which is not matter of interpretation. This is established by the laboratory selling the test. Testing for research purposes does not come under CLIA regulations.
If VIPdx required that all tests were ordered via a doctor, then any doctor on the UK register who ordered such a test would patently have failed in the professional duty as defined by the GMC (and now MPTS ). Of course if VIPdx were actually accepting orders direct from patients, or if some non UK based doctors were merely acting as order agents for a fee that would be a different issue. The role of R.E.D Labs (Belgium) becomes relevant in the latter case because they acted as a European agent for VIPdx, and it is therefore reasonable to ask whether any of the doctors (Profit and Loss ) associated with R.E.D labs participated in a ‘sign off’ service, something which might be considered unethical.
I can't remember now how the same would have applied (or not) to the specific research that occurred in the UK, as part of the WPI programme I think it was. Presumably the collection of blood, processing, and revealing of results were not patient specific and therefore no UK doctor was involved in the process.