Tying a weight to the steering wheel is frequently alluded to but never outright spoken of in most Tesla forums, moderators will ban people who say it since, as the article says, it's incredibly stupid (and damaging to one's self, and Tesla, to do so).

The fact that the driver's seat weight sensor isn't used to disable AP is a silly oversight and should be fixed. Multiple people have suggested that the internal camera above the rear view mirror could try doing eye tracking, but I actually doubt it would work effectively from that angle.