I've seen that video. The cast-on is identical to what Amy has on her site as "Norwegian".
I believe that people who label it "German" are incorrectly confusing it with the normal German longtail cast-on:
That cast-on is not as stretchy as the Norwegian.
I have Priscilla Gibson-Roberts' book "Simple Socks, Plain and Fancy", and in that book she refers to this cast-on as "the old Norwegian sock cast-on", just as Amy does in her video. Since PGR is my sock guru, I tend to go with her labelling.
Bottom line: the Norwegian cast-on and the German cast-on are both long-tailed and are very similar, but the Norwegian cast-on (incorrectly labelled as the German cast on on the hypknitism site) is stretchier.