I don't believe this would work as advertised: because if the exposure is set on the scene pre-flash, then the faces and background should be normally exposed and only the retroreflective clothing should be blasted to white if flash is used for that photo.
It would probably would look more like the link below in reality:
http://i.imgur.com/i0HJIcG.jpg

Wasn't a Sherlock Homes story first published in 1887?
This would mean that neither Tarzan (1912) or John Carter (1911) were the first modern superhero.

Do I really want fries with that?