I think it’s pretty widely established that, as far as raising children goes and the “infractions” are minor (throwing with toys, screaming), the correct strategy is to reward good behavior and ignore (as in: not acknowledge or react to) bad behavior.
These are college students (ie, legal adults), not children. This professor went way too easy on them, he should have failed them, especially the person who plagiarized the “repentance essay”. If I’d had taken the course I’d not be happy knowing I’d done everything the right way and those who cheated still ended up with an A+ (he mentioned this happened). If anything it would make me lose trust in my education.