Thanks, Rod. After reading the article, I infer that the cause remains unknown. The spacer fix is based on the assumption that the problem is due to friction: the accelerator pedal sticks with the throttle in a partially-open position. A driver could deal with a stuck pedal by pulling it from behind with his foot hard enough to overcome the friction.
If that's not the case, and in the fault condition the throttle goes to full open, then the real cause would seem to be electronic, not mechanical. I wish that the reporters were more curious and asked better questions.
Gordon DavyPeoria, AZ