She had symptoms, but how did he verify her claim that she felt them in the presence of electrical/wifi? I wouldn't presume to say it's not possible to be sens

She had symptoms, but how did he verify her claim that she felt them in the presence of electrical/wifi? I wouldn't presume to say it's not possible to be sensitive to electrical emissions. I would like to know exactly how he made the determination that the woman actually felt symptoms that were only present if there were actually emissions. Some method where the emissions were covertly and randomly toggled on and off. It seems to me that if she can't tell when the emissions are present, it may point to an underlying psychological problem.