Intent matters, and methods matter. But I think what the friend is missing is that the methods aren’t bad; op is using methods developed from scientific analysis of abused animals with the intent to ethically care for them. Coming back to intent, she clearly wants to help this guy who her training is identifying as having some kind of background of abuse. The methods might be a little crude in the sense that they were developed for animals and not for people (who are animals, but animals with several distinct qualities from other animals, like the ability to communicate complex ideas), and there are different, more well-adapted methods for people, but they’re only crude in comparison to those modern human-focused methods. They’re still quite effective, and I would still consider them ethical for use on humans when paired with an altruistic intent, which she seems to be conveying. As long as she still views the guy as fully a person, a peer, then I see nothing wrong here.
-Listens to what he means when he is speaking -Pays attention to his nonverbal cues about his emotional state -Respects his boundaries and only assists him in expanding them, not demanding he do so -Rewards him for engaging in new healthy behaviours that he finds uncomfortable
Fellas, is it being an asshole for checks notes engaging with your partner?
People forget that humans are just animals (that can sometimes reason and talk). I still stand that dog training guides make better parenting books than many parenting books. At least up till around 3 years old.
The extension of this to adults is more challenging. Intent matters. This could be used abusively VERY easily. That is not happening here, however. With great power, comes great responsibility.
It’s also worth noting that, if you use this, plan out how you will explain it later. A panicked, “oh shit, (s)he caught on!” will look bad, no matter what. A calm, thoughtful, positive explanation, delivered with confidence will likely get a lot more acceptance.
A: “Ok, what’s with the M&Ms?”
B: “You’ve noticed then. :)”
A: “…”
B: “I noticed chocolate made you happy. I also noticed you were trying to overcome some negative habits. I decided to help. Whenever you put effort in, I rewarded it with a bit of chocolate. It makes you happy, and helps you lock a good habit in better.”
A: “… You’ve been conditioning me?!?”
B: “Yes, don’t you like the improvement?”
A “… yes, but I’m not sure I should…”
B: “M&M?”
You could also be even more cautious: “I noticed that they cheer you up, so I try to have them on hand for when you’re feeling down.” No mention of conditioning, wholesome, hard to argue against.

