Interesting. If we can assume the experimenter's failure to enforce the rules was mere clumsiness or incompetence, rather than an indicator of underlying intentional manipulation of the experimental conditions à la Stanford prison experiment, this can be interpreted in many different ways.
The (eventually) disobedient subjects were better at respecting the experimental process they were given than the "obedient" ones who went all the way to the maximum voltage. Why was that?
Could it be a sign that the disobedient subjects were on average more concentrated on the task at hand (smarter? less stressed? better educated? more conscientious?) than the ultimately obedient ones, and therefore were more likely to realise they were "hurting" the alleged learner and stop?
Or could it be that the obedient subjects were more likely to realise there was something fishy going on, suspecting the "learner" wasn't really being shocked, and thus were paying less attention to the learning rules?
Or was it, as the article suggests, that the obedient ones may have shut down emotionally under pressure to follow through, and their mistakes are the result of that?
Or were the obedient ones more likely to be actual sadists, who were enjoying the shocks so much that they didn't even care if the "learner" didn't hear their question, giving them a greater chance of shocking them again?
Unfortunately I think the Milgram experiment has become so entrenched in popular culture that there's absolutely no way it can be properly repeated to explore these questions.
The Milgram experiment also couldn't be repeated today as it was completely unethical. It caused huge psychological distress to participants to the point that some participants had seizures.
My guess is that it is the pressure to conform working in multiple ways.
The reading of questions while the subject was screaming is acting in a way that seems like that it is a performative action of conforming to the pattern and that the failure of the pattern is caused by the answerer failing to conform to the pattern. That makes the shocks a punishment for failing to conform. The questioner has a facade of doing the right thing by going through the motions, even though they are breaking the rules by doing so, because if the other party were compliant that rule wouldn't have been broken. That the shocks were painful would feel appropriate to those who had a strong sense that nonconformity should be punished. It is less them following the rules and more them assuming the intent of the rules and permitting abuse because the intent was not their decision. It might make them less willing participants to the abuse and more 'not my problem' active participants.
The reason you have psychology experiments with controls and parameters is that extracting definite conclusions from the simple observation of human behavior is extremely difficult given the wide variety of individuals, groups and cultures.
Once you have an experiment that degenerates into just an event, a situation where the controls have failed, you come up with many potential conclusions but you've lost any science-specific-conclusion to the observations and you may as well look any series of events.
That said, I think experimental psychology just generally fails to establish enough controls to merit the scientific quality it aspires to.
It really calls into questions the conclusions drawn from the last 50 years. Here's the ones disproven I remember:
* kids grow to be rich because they accept delayed gratification
* alpha males are the leader of the pack and all other males are useless
* people accept violence if there is a higher authority which justifies it with a reason
How many people suffered or delivered suffering because of their beliefs in the above?