So how do you know that the drawing is inaccurate? Do you have a better one?
I am a lousy artist but if someone drew me a sketch of ahuman I coudl make the lines actually go to the body part they should. I can draw a line to the elbow instead of to the arm like he did.
I also would not put the word exit right after the arm to indicate that is where it traveled next after the graze. Moreover I would note the wounds to the side actually referenced in the report.
A bullet that was traveiling towards Nevill's side grazed the elbow, struck his side causing damage entered his body and lodged in his abdomen. It broke into fragments inside of him and these fragments were not fished out. That is what the rpoert indicates. The best way to draw this in a diagram I don't know but showing his arm hit not his elbow certainly is not accurate.