I could have _easily_ loaded it with the trigger lock attached. The trigger lock does not prevent insertion of full magazine, and work the slide to chamber a round; at that point, sufficient pressure on the trigger lock (most easily achieved by placing the back of the gun on the floor and pressing straight down with both hands, blowing one’s own head off in the process).
Anyone who works so hard to defeat safeties isn’t really an indication of a problem with guns.