Public Enemies (2009)

Factual error: In one scene, focused on a period wood-staked pickup truck parked on the street, you can see clearly a modern Jeep Grand Cherokee parked on the other side of the street.

John Dillinger: I like baseball, movies, good clothes, fast cars, whiskey... And you. What else you need to know?

Trivia: Baby Face Nelson did not die as was depicted in the movie; he actually escaped from Little Bohemia and outlived Dillinger by four months (Dillinger died in July, and Nelson the following November). Nelson received mortal wounds in a shootout with two FBI Agents (who died as well). Nelson died that night after escaping with his wife and associates; his body was left in a ditch and discovered by the authorities the next day.

Question: How was John able to communicate to Billie where he'd pick her up when she left the apartment dressed like a man? Their phone was tapped so he had to tell her somehow. Also, in the beginning, who was the woman with the little boy who asked John to take them with?