A misunderstanding? According to tradition, Mansa Musa's predecessor Abubakari II sailed west and never came back, causing Musa (Abubakari's vizier) to seize the throne as emperor. But Musa never sailed or sent ships out to sea himself.

Can you link the show you were watching?

Does he say anything more specific than "Some evidence?" Crossing the Atlantic is a major claim and generally when people make it they are indulging in wishful thinking.