Frustrated,
False accusations of countermeasure use are not unusual, and are probably becoming more common as polygraphers become more concerned about countermeasures. Since the launching of AntiPolygraph.org and the publication of
The Lie Behind the Lie Detector in 2000, polygraph countermeasures has been a hot topic in the polygraph community.
The pressure cushions you described are intended to detect physical countermeasures. I suspect the device in question was this one, marketed by the Lafayette Instrument Company:
This device seems to be more useful as a scarecrow to deter countermeasure use than as a working device for countermeasure detection, however. There is no published research supporting the ability of polygraphers to detect countermeasures using these pneumatic cushions.
Although you didn't move during your polygraph examination, your weight distribution over the pads may have shifted during the course of your polygraph, and your polygrapher may have interpreted this as a countermeasure attempt. By the way, pushing the galvanic pads down into the armrest is a crude -- and ineffective -- countermeasure. No one who has researched polygraphy is likely to attempt this.
By "early responses," I suppose your polygrapher meant physiological responses beginning before the asking of a question. I'm not sure what your polygrapher meant by "variable responses." Perhaps he meant that sometimes you responded to a certain question and sometimes you didn't.
I wish you well in your interview next week. Please let us know how it turns out. In the meantime, if you'd like to learn more about the polygraph process, see Chapter 3 of
The Lie Behind the Lie Detector.