It doesn’t matter what he thinks he knew. Anyone who picks up a gun should remember an important rule: ALWAYS assume the gun is loaded! So if you are to point a gun at anyone even for “acting” or playing pretend you absolutely need to check for yourself that there are no bullets in there. Seriously it takes a second and in this case could have saved a woman’s life if only Alec followed such gun safety rules and not assume that responsibility on anyone but himself.