They are covering for him. Making a “he’s not a terrorist” excuse for him.
I have sat outside playing with guns (i.e. cleaning them) while the rest of family watched TV inside.
I get it, but would your family described you as mentally ill? Then do nothing while you sat outside handing what they themselves described as a, “Machine gun”? If someone I knew was mentally ill and I saw them playing with a ‘machine gun’ I’d run and jump out the window.