I'm actually having more problems with the foreshortned arm. The face is still ok, though.
What problems? The foreshortened arm's width is partly obscured, so it's hard to say whether it's bad or good unless you refer to length.
Also, to the Highway Go-Go appeal, that argument could be applied to literally any flagging or not approving any image on quality grounds. If quality is going to be a standard at all, then some judgement on art style is necessary. (And "you" who? You seem to imply a personal animus about an anonymous flag.)
How can you prove that? Do you have some sort of program that can calculate the proportions? Or is this all based on your eye?
Approving is a subjective process. That's written everywhere. So yes, you can say that I'm the opinion that it looks to long. (Btw. flags are also still opinions even if they should be written as neutral as possible)
I fear that the arm is too long. Unless proven otherwise, I won't re-approve this.
It doesn't stand out to me as such. Foreshortening makes things larger in all directions, so something "closer to camera" would appear longer as well as wider. The only thing I would think of, really looking at this, is that the proportion between upper arm and forearm should be more notably distorted by foreshortening.
That said, the nose and mouth, combined with the wide spacing of the eyes are what's keeping me from a re-approval, so enh...