First of all, WOW. Nice photos, 5DIII, 50mm 1.2!. I apologize if you already know this... and, ok, this may be getting into the weeds a bit but if you have done all of the other things mentioned by the others... and you are still not getting satisfactory focus there is one more thing to check... And this may not apply to the particular photos you posted... but (as you know) with the 50mm 1.2 you can get an incredibly shallow depth of field with the aperture wide open (i.e., aperture set to 1.2). The 5dIII auto focus does the best it can... however, with the lens wide open, "back-focus" becomes more obvious.

Take a look at the attached photo taken with a 35 mm 1.4. If the image quality doesn't get reduced too much, you will see how the hair in front of the eye is in sharp focus but one inch away, the eye is very soft. I focused on the eye but the photo looks like I focused on the single hair hanging down in front of the eye. I would never have known I had a back focus problem without this photo!

You may have since already found this out, but, there is a way to test for "back-focus" and there is a way to correct it on the 5DIII. Too much to explain here, but look it up if you haven't already...