Firstly, the Phantom 4 or 3 cannot fly at that altitude due to firmware restrictions. Secondly, to be able to tell the difference between a Phantom 4 or 3 (or probably any other drone) at 250 knots is impossible.
Not so. Geo-fencing is easily disabled and so is the altitude restriction. A booster pack is available to give extended range. This encounter was just south of Tung Lung island in Hong Kong's airspace, about 1 mile south of the TD VOR, in controlled airspace. That's quite a way from the airport and I suspect it was outside the geo-fencing, but it was still in controlled airspace. Some of the terrain is up to 3000ft in that area, so the operator could be on high ground. As for being a 3 or a 4, as I said before - it doesn't effing matter. It shouldn't have been there! This incident was filed as a MOR.
In Hong Kong, drones come under the ordinances pertaining to model aircraft and are limited by law to 160m altitude. This is the fourth close miss my airline had had with drones in as many months in HKG airspace, with one at 4500ft and another at 300ft on the approach
As part of my office job, I also sit on one of the airport safety committees. Last week, the meeting spent a lot of time discussing the issue. All I can say is that further restrictions are coming the aviation authority are pressing the Government for further protection for aviation thanks to a few irresponsible drone owners.