If they landed on one of the islands likely to be passed on the way into the Caribbean, they might have indeed been captured by cannibals. I think the island GUadalupe was mentioned with that kind of culture in the 1421 book.
Giovanni Verrazzano, who explored the east coast of the present-day US in 1524 (Verrazzano Narrows in NY harbor is named for him), was killed and eaten by cannibals in 1525 when he made the mistake of going ashore on one of the Caribbean islands.