Looks like you didn't bother to isolate.
Regardless, TF2 models aren't the best to practice shading on.
On his left arm I can see some serious isolation errors.
No, nevermind. I can see isolation errors everywhere.
Didn't know, that I should.
Edited:
Dirf, I didn't isolate it :O
Very nice posing, but the shading is unnecessary, TF2 pics don't really need it.
You only wouldnt need to isolate if the light was being reflected off a surface like glass or something.