Nitpick: Vivien Thomas was not a doctor and in the 1940s was doing research with Alfred Blalock on “blue baby syndrome”. Their work was pioneering and important, but Vivien Thomas was not recognized for it at the time. So I doubt he would have been shown in a film of prominent African-Americans.
Also, the narration identifies the man as a “leading New York City surgeon” and Blalock and Thomas were working in Baltimore.
The narration also mentions "Admiral Peary planting his flag at the North Pole.’ Only, he probably didn’t, and he wasn’t an admiral, so apparently it’s a mash-up name with Admiral Byrd. I doubt the writers thought anyone would be fact checking them seven decades later.