My own personal experience (I am a Master Plucker) is that plucking is caused by only one thing: creeping. It could be that Arne is a Senior Master Plucker, and has discovered other ways to do it. I've always wanted lessons from Arne, and maybe this is one of the things he could teach me, as I've always wanted to increase my plucking skills. (Just kidding!).
Creeping means that you reach maximum tension in your draw, whether (correctly) through back tension or (incorrectly) through using your arm muscles, and then relax the tension slightly before releasing the shot. As you relax tension, you suddenly realize you have to get the shot off before you totally collapse, and so you try to pull back in a desperate attempt to save the shot and pluck the string, resulting in a right or right high miss for a RH shooter.
The solution is to keep all the tension you gain pulling, whether you're pulling with the right or wrong muscles, until you release the shot. I do it (when I'm not trying to perfect my pluck ;-) by drawing the string back against my eyebrow and maintaining the pressure I feel on the bone under my eyebrow. It's hard to know if you start creeping unless you have something to gauge it by. If you do feel yourself losing tension after you reach full draw, the recommended solution is to let down. I, and even some GOOD archers that I have seen in videos, will sometimes flinch, recover, flinch, recover, and then shoot the shot, but I'm sure if you could make yourself do it, it would take less energy to just let down and start the shot over.