Dogs pretending to ignore they’re transgressions

If I leave the house and come home sometimes my dog will have managed to get in the trash and pull something out, or rooted out a package of food in my room I forgot to secure out of their reach. To preface they are a rescue dog but I’ve seen this behavior in most every dog I’ve met. But if I come home and there’s say a chip bag on the floor all torn up from her finding it and tearing it apart to get to the crumbs inside, I don’t even have to say anything, I will just pick up the refuse from it and she will immediately tuck her ears and go in her crate (it’s her safe space anytime except when I want her in there) or retreat away from me and avert her eyes to me and the thing she did. I don’t yell or even get mad really I’ll just say “what’s this and move it toward her and she just looks the other way. I’m curious why dogs do this instinctively and refuse to acknowledge they’re screw ups.