I'll address this mainly to GregMc since this is exactly his field of expertise.
GregMc, would you agree or disagree with these 2 statements ?
(Anyone is welcome to chime in, but since GregMc is an expert I'd like to hear from him.)
1. The model in the video is (reasonably) anatomically correct within itself as a generic human figure. (Its most likely a standard library object that came with the 3D software.)
2. In the video, the 2 right legs (model and Jeff) are close to parallel, within a few degrees.
Well frankly I think the model and photograph are poorly aligned.
I'm also concerned at the idea of a "generic human figure".
Ergonomics reveals that human forms vary wildly. Unless you have a body proportion match and an exact pose match then it's not informative. Also we don't know how the model is rigged.(skeletal animation setup)
I come across rigged characters where the rigger has simply not bothered to study anatomy, with jaw pivots placed at the corners of the mouth. Don't get me started on "backwards knees" on quadrupeds' hind legs... (those are actually heels)
Do these hips/thigh bones have the correct joint pivot spacing?
I sometimes have to fit 3D digital human models to live footage (and other species too) I see clearly that there has been little attempt to match them accurately here. Certainly the pose doesn't match. If the major joints are not EXACTLY aligned then the exercise is pointless.
Even if someone had managed to find a 3Dmodel human that was an exact proportion match to Jeff in every way, it would still likely not align accurately if the digital camera was not an exact match . ie, match filmback, format , lens etc. There is software that can solve for camera to interpret footage and produce a virtual camera that is THEN used to "film" the 3D model inside the virtual environment. Obviously a wide angle lens imaging a character close to camera will give completely different alignments to a long lens further away, even when viewing the same character in the same exact pose.
Looking at the skin/meat outline of the leg , particularly one just flayed by a bomb is inappropriate as a guide to the orientation of the bones underneath . Have a look at the footage of the fellow munched by a Bull shark on the calf. Skin and muscle hangs like a stretched pullover on a coat hanger if the integrity of the elastic skin covering is compromised and there is ligament/tendon trauma.
Have a look at a vid of someone having their thighs massaged (you know you want to!) and notice how without the bones changing position, the outline and bulk can move considerably.
Also as the guys have already stated, this is a totally POINTLESS exercise if you WANTED to fake it.
No one would try to attach prosthetics in the field!!! It takes hours usually and can be brought down to minutes but the suggestion that such perfectly typical and accurate injuries would be prosthetics applied in situ surrounded by the public in fractions of seconds is totally nonsensical.
What is possible as others have already mentioned is to have preprepared prosthetics already applied that are activated with squibs etc. Some of my Colleagues did the gory amputation effects on saving Private Ryan. No one in their right mind would try to apply anything in the MIDDLE of an action scene as is being suggested here.
You can claim these were already attached prosthetics hidden under clothing that is then shredded by hidden squibs but why bother when there was ALREADY a decent bomb present.
Bomb effects close to actors are achieved with air-cannons powered by large tanks of compressed nitrogen, with a lot of ground disturbance required to dig in conical tubs full of soft debris and fullers earth, etc Not easily hidden in a paved or concrete roadside setting, If you did accidentally have hard debris in an air cannon setup you risk doing things like... shredding actors legs to the bone....
As other have already said, why on earth would you employ often emotionally fragile makeup artists and actors and risk them having public tell-all pangs of remorse and mental breakdowns. Know any hair-dressors that are taciturn and glum and can keep a secret for decades? Me neither. Makeup artists are the same. Do they show the Boston Bombings in their CV/portfolio to get their next job?
So much easier and cheaper and fool proof to just blow up real people with a real bomb !!! Or do you think the gov't isn't evil enough to do such a thing?