Oh, that helps me. I thought it had something to do with rotating the palm. Why did they go into all the detail of the ulna & radius crossing?

The counter example they gave was the elephant - but this video [1] of elephants walking looks to me like "bunny hands", at least to a degree.

[1] https://www.youtube.com/watch?v=yf1K63tc1bY

That video has such terrible image quality that it isn't possible to see the elephants' toes.