This isn’t entirely true. My dog was a demo dog when I was a trainer and therefore she had to obviously be top notch with her own training… which included passing the AKC Good Citizen test (not easy… one single mistake and you fail). And even with all that training she has gotten loose before. At my dads house she actually managed to jump up on the door one day and opened it (was the lever style door knob). Then went outside and roamed the streets for a few hours while I wasn’t home.
Sometimes shit does happen and a dog always has that curiousity that you will never get rid of.