I have had 9 skyhook cutaways on sub 100sqft canopies and had linetwists on reserve once.
I think body position when cutting away has a lot to do with getting reserve twists.
That video you linked to, the guy barely tried to get out of the twists. I didnt read what height he was at and if he had altitude to have a go. Maybe he just didnt want to try for long. Fair enough.
But letting the canopy settle for a second makes it far easier to kick out regardless of whether it is diving or not.
Anyone flying a high-performance canopy should have the ability to be relaxed during a mal and be altitude aware enough to know if you have time (and how much) to attempt to correct the main before going to your last chance canopy.
A very fast spinning canopy cutaway will throw you straight out away from it, and provided you aren't flailing round like a muppet and are relaxed, there is no reason the reserve wont come out untwisted and on heading.
I dont know where that cutting away quickly notion comes from but that seems to me to be the best way to try and get reserve twists.
Far better i reckon (if you've commited you are definitely cutting away and you are not critically low) to let your body settle its orientation, whether that be skywards (spinning on your back) or facing the ground.
One more thing: everyone you know with both a skyhook and a high-performance canopy gets reserve twists everytime?
Maybe its not the skyhook they need to get rid of!