Nice paddle bow, Intresting, however the way he is doing the sinew would be a pain to do that way and doesn't saturate the sinew enough to get maximun shrinkage and potential of the sinew. Maybe why they had to reverse string the bow for the reflex.
If you soak the sinew in warm glue for several minutes then strain between the fingers it becomes much more pliable (like wet hair) and easier to apply, and then it will actually shrink and pull an otherwise flat bow into a perfect reflex. It is also much easier to press the sinew into the wood when presoaked.
Not trying to discredit the video just wanting to help some to know there is much easier and better ways then that.