Or tie it in by the tip as the very first step, with the stem cupped up facing out over the hook eye. Pull it up to wrap when the rest of fly is finished.

I tie most feathers, other than dry fly hackle, (and always partridge) in by the tip (either first or last, depending on the fly) I've tried trimming the tip first like he did, but I usually end up pulling the feather out.

Which common rule do you think he violated in putting the dubbing on the thread? Yes, he did twist in both directions. but that was to distribute the dubbing.