Actually none of the sub-questions you asked matter in this case.
The researchers already functionally conducted an AB study - http://en.wikipedia.org/wiki/Single-subject_research#A-B . In this case, they saw behavior with the machine turned on that went away when they turned the machine off. If they want to confirm that some aspect of the machine (and it doesn't matter if it's noise, smell, light, or some mousey-sense that we are completely unaware of) they could extend it to an ABAB study, by turning the machine on, noting the incidence of 'crazy' behaviors over a period of time, then turning it off again and noting the incidence of 'crazy' behaviors.