Rosenberg said she developed her theories by analyzing publicly available evidence and with input from other scientists, and from "inside" sources.
and later in the article -
"There is explicit speculation floating around the informed bioweapons community in the United States that this might have been diverted from a U.S. biodefense program," said Wheelis.
sounds like someone planted the seed of the idea in her brain, knowing that it would take root and that her left-wing bias would nurture it predictably.