Imagine a thermostat that... Doesn't do the temperature the…

Imagine a thermostat that... Doesn't do the temperature the operator sets it to, ...And lies to you about what temperature it is!
Set to 71 farenheit.
Was 71 for a hour or so just to make you think it's working. 3 hours later it's Actually 75 according to the (accurate)thermometer. But GOOG Nest Says it's 71.