Sgt Danny Nightingale, a special forces sniper who served in Iraq and Afghanistan
Been a loooooong time sice trophies like that were permitted. When I was coming back from Desert Storm, we were explicitly told we would not be allowed any sort of battlefield trophy; anything like that either had to be disposed of or turned over to the command. Under special circumstances, and if the weapon was explicitly de-milled, then he might have gotten permission from his command to keep it. However, as it stands, it sounds like he specifically went against similar blanket orders, and military law being what it is, he got exactly what is prescribed in such circumstances.