"He could have added that he who claims a miracle is a bloody liar."
You see Steve, here is where you depart from logic and science.

You make this pronouncement with out evidence, data or or analysis.

Both Musket and Hawk have give examples of how someone might perceive a miracle to have happened. If they believe it was a miracle, they can truthfully claim that a miracle had occurred.


likewise,   If a kid with cancer goes to Lourdes and does whatever they do there and and his cancer goes away. You could say that it had nothing to do with the prayer but not being a Dr. and not having witnessed the event you cannot completely rule out a miracle. Maybe someday we will be able to say that such things happen because of some internal mechanism of the body, or some other as yet unexplained factor. But as of now you cannot rule it out completely.