You can currently run Hotz' software Openpilot on your car and many do. The general consensus is that it's as good as Tesla's AP2. There are hours of footage of Openpilot driving by actual users (not PR videos) on Youtube.
It most certainly does "come close to even an alpha version of a commercial product".
It's one thing to have a few tech-savvy enthusiasts installing your system and using it a bit with a good understanding of its strengths and weaknesses. It's another thing entirely to let tens of thousands of random members of the general public use your system for months on end with minimal-to-no training and no technical insight into it.
But I was just making the point that it's definitely at least Alpha software.
So, he could have gotten the same results with a webcam.
My understanding is that these depth cameras create a 3d point cloud and use the rgb to map/overlay color onto the 3d.
"infrared camera" is falling quite a bit short of a description. In fact some have used a single IR emitter to light the face up in the dark and/or as a trick to ignore surroundings but then it's not much better than a picture. Here it's an IR dot projector whose projection gets captured by an IR camera and subsequently extruded as a 3D volume, Kinect-style. I don't know about what Windows Hello mandates for face recognition though (also, it can be iris or fingerprint as well as face, which just makes things more confusing).