 FACT: SPOILER: When Quint was spooking Brody in his boat at  nighttime on the first night of the attempt to kill the shark, Quint  tells Brody a USS Indianapolis story. In the story, he mentions that  sharks eyes roll back into their heads and only the whites are seen  when a shark bites someone. That is true and the shark does it to  protect its eyes. However, it did NOT do that when he was chewing  the life out of Quint at the end.