Haptic feedback is a nice idea, but I wouldn't be surprised if the software people screw it up. I've lost count of the number of devices and software UIs that give incorrect feedback: they sometimes beep/flash when the change has not been received, or they sometimes register the change without the usual beep/flash.

Have I encountered a device/UI that errs in both ways? Yes, I think I have: a microwave that beeps and increments the time when you press a button labelled "10 s", but if afterwards you squint carefully at the almost illegible LCD display you find that the number of beeps may differ from the (time / 10 s) by a positive or a negative small integer. There must be two separate button-press-detectors: one for incrementing the time, and one for the "feedback".

Do we have a term for this phenomenon? It's common enough to deserve a name.