I showed this to my sister, an Honours graduate in Fine Art, and Art Teacher....and her comment was that it would have to have been traced, as it's 'impossible' to evolve a drawing in that way....in proportion, scale, form, etc...without setting some guidelines.
The composition is too uniquely distinctive as an awkward pose to be anything but 'traced'.
I tend to agree....the colour fill and shading is exactly as I'd apply conte in my drawings, but the preparation linework is missing...
Doesn't mean it ain't a great animation...if only I can work out how to save it to HD so I can run it at will...