Yep! CT scans and clinician's experience is more reliable than any tests for COVID-19 diagnostics (which should only serving as a definitive confirmation). This also why I believe human doctors are still unbeatable by AI
Because you hypothesize that they can rapidly learn new, not very distinctive patterns without much data?
Of course not! We've got half a million cases now, hundreds of thousands cases in hospitals, and hundreds of papers published in all the medical journals. So yeah, data is rich.
Regarding CT scans .. machine learning will be so much better than humans in classifying those once enough data is available... it‘s completely out of question for me as an ML researcher.