Only wild if you assume that everyone has the same likelihood of having proximity to such an event. But people involved in smallpox research have a much increased chance because they have (physical) proximity to the places this can happen and those that find them have (secondary) proximity to those that have higher (physical) proximity. And Gates funds lots of these researchers so he has a very, very high likelihood of being withing a few steps of relation to something like this. Think centrality from graph theory. Gates is a very central vertex.