Why would it be an outlier? Why would the military consider women for that position if they thought they might be unsuitable in any manner? To appease the yet inexistent Women's liberation movement? Also it's not an outlier, search for photos of computers of the same era, and you find quite a lot of women.
My guess is that it's much simpler. Designing the ENIAC was a man's job. Perhaps programming it was the unglamorous chore, a sort of maintenance task somewhat akin to sweeping the floor. Or maybe because they saw similarity with a switchboard operator.
Later, programming gained prestige, so obviously men wanted those jobs and would have the advantage.