This is a tough question. The official line for Christopher Columbus was that he had found the Indies, the destination defined in the capitulacion he had with the Catholic Monarchs. From a legal standpoint, at least during his life, there was no hard evidence to prove him wrong since Europeans did not know the full extent of what they called the Indies.

Scholars, and most knowledgeable sailors, knew that he had not travelled any where close to the distanced needed to reach the Indies. Yet, they had no specific proof that the Americas were not part of the Indies. Eventually, well after Columbus' death, the preponderance of evidence made Columbus' claim moot. His heirs continued to press his claims based in the original contract, noting that even though he did not reach the Indies he did serve the monarchy by expanding the kingdom.