Factual error: Marie Curie did set up mobile X-ray units during WWI, but they were not on the battlefield, but in field hospitals, well behind the front lines. (No one wants a field hospital to be hit by rifle or artillery fire).
Factual error: Three B-29 bombers took part in the Hiroshima mission, flying together at 31,000 feet. Enola Gay carried the bomb, Greate Artiste carried scientific instrumentation, and an unnamed third plane carried photographic equipment. The bomb detonated at 1000 feet above the ground, so it is highly unlikely that anyone could have seen it falling.
