I once lived in a house where this happened fairly often. We had a refrigerator with one of those push-down door handles. The cat would jump up and hang on the handle, pulling it down and causing the door to swing open. Then he and the dog would climb in and eat my housemates’ suppers.
Here they’re only stealing cookies, and probably confused by the patzer standing there with a camera, filming them. It would confuse me if I were stealing cookies.