Looks to me like they are expounding on the manner in which this device helps arrow flight, making the arrow hit straight on and thus get great penetration.
Looks like by "shooting them out of a tube" it reduces the paradox, as stated above and it appears to me to be a way to get their cane arrows to be flying well without the benefit of tuning as we are doing here.
The slo-mo video of arrow flight difference is a clue.
Beyond that. . . it is humbling to see them hittting those targets at what looks like a mile or more ( OK 100 - 200 meters . . . May as well be a mile).
ChuckC