Of course. Silly me. OCUK Motors, the only corner of the internet where Caveat Emptor is no longer a thing...
Of course technology has moved on, but should we, as buyers, be absolved of any responsibility as to what we buy, simply because of ignorance? No. If we want something, we should be able to tell if we are getting it or not. There is CLEARLY going to be a way of telling the difference between adaptive xenons, and projectors on an X5. I have never needed to know how, but if I did, I would research it. In this case, the OP's father even got a picture, which, as Fox has already pointed out, is one way of telling, externally, the spec of the fitted light units.
Moreover, Fox, are you really trying to suggest that there is no method for the driver to control whether the adaptive lights are on or off? I suggested that there will be a control for this either on the console (most likely near the light switch) or on a stalk. Certainly on my e91 it was stalk controlled. I would expect similar on an X5 to be honest. There has to be a way, so it has to be able to be determined from this. Just because I haven't looked seriously at an X5, and so don't know exactly how it works, doesn't mean it doesn't work in some similar fashion. And if I was looking for such a car, with such a spec, and was willing to reject cars without this spec, surely the onus would, to some degree at least, be on me to know the difference? It is MY money buying it afterall.
And if I'm likely to be spending £25k+ or whatever this AUC X5 costs, should I not be expected to do at least some basic research into what I want from it? The argument that the average person doesn't have the time to research a purchase on this scale holds no merit, unless your Elliot James or someone with unlimited funds and no clue. In which case, the xenons probably aren't as important as wheel size and the shade of white.
As I said, in this case, I agree the OP's father did things correctly, for the most part. He had written confirmation 3 times, and should easily get the car swapped out or returned. However, surely a quick comparison of the picture of the light unit that was supplied, and one known to be of X5 xenons would have been enough to determine the salesman was a numpty.