Some (Sungenis in his new film (https://www.youtube.com/watch?v=AbcLf1cDHVA)?) think that a single crucial experiment (
experimentum crucis) can falsify a physical theory; however, all a single experiment can do is show that at least one of the physical theory's assumptions is wrong, but it cannot say which.
The French Catholic physicist, philosopher, and historian of medieval physics Pierre Duhem (https://www.encyclopedia.com/people/history/historians-miscellaneous-biographies/pierre-maurice-marie-duhem#1) formulates this non-falsifiability thesis (https://plato.stanford.edu/entries/duhem/#AgaNewMetDuhThe) as follows (
Aim & Structure of Physical Theory p. 185 (https://archive.org/stream/AimStructure/The%20Aim%20and%20Structure%20of%20Physical%20Theory%20-%20Duhem%2C%20Pierre%20Maurice%20Marie%2C%201861-1916#page/n223/mode/2up)), when describing an experiment that contradicts theory:
Quote from: Pierre Duhemthe only thing the experiment teaches us is that, among all the propositions used to predict the phenomenon and to verify that it has not been produced, there is at least one error; but where the error lies is just what the experiment does not tell us
See: https://www.youtube.com/watch?v=hM83cBa9wDM
(The development of the doctrine of the Trinity is mentioned @11:54.)
Interesting...I had not heard of the term falsificationist. That means then from what I see that not everything hinges always on one single action.