That miracle was the source of his vocation. At that point in his life, being a medical student, he understood science.
He understood, I am sure, how natural law was suspended by the miracle he saw.
Sometimes it is hard to accept the supernatural.
If you see a saint levitate [many instances could be named], you and I might accept it, but others would on in disbelief.
Of course, the famous story of Saint Joseph of Cupertino was that he forbidden from levitating until they needed some bells hung in the bell tower. Then he obeyed the orders of his superior... And he hung the bells through levitation -- just by praying.
If that would be shown live on TV today, people would ridicule as some sort of trick such as hidden wires...