Example of a fallacy

Interesting developments in the Swine Flu outbreak this week. China and Russia have banned imports of Mexican pork, despite the fact there is no evidence that the virus is passed on through meat products. The Mexican government has complained to the World Trade Organisation as a result.

I saw this quote from Nikolai Vlasov, the Russian chief veterinary inspector:

"We are constantly told that pork is not dangerous. But at the same time, nobody has proved that it is safe."

Why is this a fallacious argument?