Veterans' right to short-barreled firearms

I read that there is a discussion now about granting war veterans the right to acquire and carry short-barreled firearms for self-defense. However, this news also mentions judicial practice where even experienced military personnel can receive severe punishment for violating weapon use rules. I am interested, if such a law is adopted, what could be the real consequences for veterans if they make mistakes in handling legally acquired short-barreled weapons? Can they also be held criminally liable, similar to what happens with active military personnel in the mentioned court cases?