I am not a doctor so I cannot judge if “no it cannot be done” is valid or not. But I think experts are allowed and expected to say “no it cannot be done” when

I am not a doctor so I cannot judge if “no it cannot be done” is valid or not. But I think experts are allowed and expected to say “no it cannot be done” when something truly cannot be done. Experts are not superheroes and unlike superhero movies (just as example) there are matters that we cannot solve in a timely matter no matter how many experts we throw in the ring.