[EricH]

Herding is never defined or mentioned in Section 7 of the Manual.

Presumably, the intention is that if you bulldoze through a pile of soccer balls that are still scattering after coming off the return while you've got one in possession, and they scatter more, you don't get penalized.

I am not on the GDC, however, and I think this would be a good one to ask the Q&A.