The "rule-breaking" isn't referring to anything the researchers were doing.
It's referring to what the participants were doing. It points out that the compliant subjects who delivered the shocks weren't always following the procedure they were given perfectly. Which is, of course, expected, since people in general don't follow instructions 100% perfectly all the time, and especially not the first time they do something.
> Kaposi and Sumeghy interpret these patterns as a complete breakdown of the supposedly legitimate scientific environment. The subjects were not committing violence for the sake of an orderly memory study. With the scientific elements either forgotten or rushed, the laboratory changed into a setting for unauthorized and senseless violence.
This feels like a huge stretch. Forgetting a step at one point or reading something out loud too early isn't a "complete breakdown of the supposedly legitimate scientific environment" -- a "scientific environment" that is completely fictional to begin with.