That is Nathan Wright doing the calling in that little video,unargueably the best speck caller on planet earth.
That is James Rathjen who recorded the video on his phone,California,fall 2007,redbone prototype call used.
I agree with the statement about trying to stay away from,hu-hu,ha-ha,lu-lu, and all the such diaphragmatic burst of air approaches,although can still kill geese.
The air like one would use to blow out a candle,a sustained air stream over time that can be shaped that has no break in the sound. Must be learned very slowly over time,not easy to do,but much more realistic once gotten a hold of. Is it easy,no,there would be speck calling aces all over if that were the case.