If you came across your dog doing something it ''knows'' it shouldn't be doing yet you gave a very happy welcome with a cheery voice, do you think it would still get the ''guilty'' look on its face and with its body language?
Yes, but it's because they've done something they knew they weren't supposed to do. I had this happen after my parrot told my bitch to pee on the floor. I wasn't mad at her at all, but she reacted like I was going to kill her. I also got very good at giving a 'look' to my male when I was fed up with his stunts, and that's all it took to make him quit. They can read facial expressions, but if their own guilt is that high, they may not believe what they're seeing.
Wrath of Grim z Dragon
"Mr. Grim"- Threaten my handler. I dare you.