The neural network isn't looking for a head, limbs etc... It's just looking for overall patterns. The soft used in the article is Yolo and I work a lot with it

The neural network isn't looking for a head, limbs etc... It's just looking for overall patterns. The soft used in the article is Yolo and I work a lot with it, and the results depends A LOT on the data you used for training. Some datasets will detect a gorilla as an human, some won't. Some even will detect two upside down fingers as a human. So if you want your NN to not detect gorillas as a human, you have to include pictures containing gorillas where they are not labelled as humans.