I was watching a comedian on The Tonight Show the other night and he made an interesting observation about automation in restrooms (toilets or whatever they call it in your neck of the woods). He spoke about how he hated it when one part of the restroom was automated but the other was not, which caused him to do things that made him look stupid.
It was a funny observation because most of us have probably encountered places like these, for instance when the flush is automated and so is the soap dispenser, but the tap can only be operated by hand. Economics probably dictates to designers whether they can use full automation or partial automation and you can’t fault them for that decision.
But, the problem occurs when you have inconsistency because of not providing visual cues or clear enough labels or affordances. The inconsistency tends to confuse users who make “mistakes”.
The mistake is in not providing the right information to the users so that they can use the product in the way that it was intended to be used by the designer. And that is certainly not the user’s mistake.