Their mandate was to show that this virus would not infect any other animals, so they set up experiments to give this answer. The desired outcome was pre-determined and the experiments were designed to give that outcome rather than to answer the question. Thirty four species were tested but only four animals per species were used - a very small group. The range of species included the kiwi and the short-tailed bat for New Zealand. The doses of virus that were given those animals are stated in terms that startle the public, but they actually are not large in terms of infectious diseases.
Researchers say that they gave each animal sufficient virus to kill a thousand rabbits.
It sounds like a very large dose, but in actual fact a single fox eating the liver of one infected rabbit will get thirty thousand times more virus than the dose to which they exposed the fox in their experimental protocol. Under terms of natural exposure the amount of virus used in the experiments is a pittance. The doses were very small and were calculated to be small in terms of actual virus particles. The usual infectious dose for a virus might be in the neighbourhood of a million viruses, whereas these researchers were giving a thousand. The reason for the low dose is that animals have an immune response if enough foreign protein enters their system so that they recognise it as foreign.