Also, Data cannot lie without the emotions chip (which afair hasn't been encountered at this point).
Can he not? He does in Clues. Admittedly he was ordered to by Picard, but I'm not sure if that's significant.
Of course Data can lie. He lied all through "Time's Arrow" about his horseless carriage engine with its "Time shift" gearing system, and about being bloody French. Whether or not they should be considered dishonest in nature, those are still falsehoods, and he can tell them just as much as anyone else, although not quite as well, it would appear