Re: Emotional damage and stress to all involved.
"how were they to know the system was setup with 2 different search terms (old and new) and did not bring up a per word result (screening + cancer) but only brought up a single term result ("cancer screening" exactly)."
I can only speculate on how *they* could have known, but *I* would have known because the testing would have included identifying records (which could have been artificial test records, or anonymised real records, or perhaps just plain real records with suitable privacy precautions taken) containing one word, and both words, and no words, together and apart, testing search terms in all the various permutations, and the results compared with the expected output based on the identified test records.
Whether by design or process or procedure or incompetence, what on the face of it sounds like a relatively simple test to consider and execute wasn't done. This is incompetence; spread across which levels (project, programming, testing, management, requirements, etc etc), I couldn't speculate, but this is incompetence.