It’s not an experiment to react to someone’s fear and trauma with kindness, even if you learned those skills through helping rehabilitate dogs. She’s not doing this to try to figure out how he reacts to the stimulus of M&Ms under certain conditions, she’s giving him candy when he’s stressed because she knows it helps him calm down. That’s just being a caring and attentive girlfriend.

Yeah, this person isn’t disrespectfully treating a human as they would a dog, they’re just respectfully treating dogs as they would a human.