BA charges 25k miles one-way in economy class and 75k miles one-way in business class for a non-stop MXP-JFK flight operated by Air Italy (IG) - which is the pricing for flights exceeding 4000 miles.

However, based on all sources I checked (gcmap, webflyer etc.) the distance is just under 4000 miles (figures range from 3980 to 3995 miles).

Therefore the award should cost 20k miles one-way in economy class and 60k miles one-way in business class.

Is this just another scam where BA assigns a random (higher) distance to a particular route to push the award into the next tier?

Or is this a legitimate "error" with the ability to get the lower pricing by calling in?