That is the point, it probably didn't take but a couple of tries before it was determined that pinching the tube at the hilt as I understand it was done, also deformed it a bit at the threaded end enough to prevent screwing the cap in. This knife may be the only example, it is the only one I recall seeing.

Although the pinched tube and square sided hilt is more attractive for many of us, the practicality of trying to maintain that shape with the threaded cap fell short. I suppose you could have used a mandrel to hold the shape at the threads but probably wasn't an option relative to efficiency at the shop. Changing the shape of hilt killed two birds with one stone. Pinching of the tube was no longer necessary, and threading was unaffected.