I was over at his house and took the dog for a walk. She's a loving pitbull, very clever.
I trained this dog when he was away on business for most of it's pup years. When we talk together and I stop, it stops immediately and sits waiting for a command or for me to continue.
I told her to sit in front of me and pretended to take out a treat from my pocket, asked her to do some paw, roll over and sit/up commands. She did them all.
I put my hand out and there was nothing there. Again, I did the same thing. She sat, gave paw, rolled over etc.
The second time she saw there was nothing in my hand, she got upset, whine barked and did not comply as easily the third time. In fact, she began investigating my closed fist pretending I had treats.
This dog understands being fooled better than normies.
I've read they were kind of like nanny dogs and were very protective of the little ones.