Sorry to sound a bit cynical, but the wound looks almost superficial (which is a good thing), and that is probably because it was inflicted by a plastic, foldable propeller. During my 12 years in RC hobby, I learned to never approach a plane with a running motor from the front, a multi rotor from above, and to always stay at a good distance away from anything equipped with carbon fiber props, especially single-rotor helicopters.
In general, the bigger the prop and the faster it rotates, the more damage it can inflict. But, that being equal, folding plastic props are least dangerous of all, as they usually only produce a series of relatively shallow, clean cuts. Solid props can do a lot more damage as their store more kinetic energy at the tip. Worst of all are thin carbon props, which can easily cut to the bone, then shatter and generously pepper the wound with hair-thin splinters. Don't ask how I know... And the wounds inflicted even by a relatively small single-rotor props are too gruesome to describe -- in addition to being large and CF, they usually have pieces of lead at the tips... So let us never underestimate the power of sharp rotating things.
To finish on a brighter note, we should all be glad that most Mavics have plastic, foldable props. And I hope lessons such as this must only be learned once, never to be repeated.