This quote is about Jackie on the plane after the shooting and she is wanting to take off and leave Dallas. There is a lot of confusion of where LBJ is, on the plane or another plane. After searching Airforce One, this is what they found.
What McHugh claimed to have witnessed next was shocking. "I walked in the toilet, in the powder room, and there he was hiding, with the curtain closed," McHugh recalled. He claimed that LBJ was crying, "They're going to get us all. It's a plot. It's a plot. It's going to get us all.'" According to the General, Johnson "was hysterical, sitting down on the john there alone in this thing."
http://www.huffingtonpost.com/steven-m-gillon/a-new-wrinkle-in-the-jfk_b_339026.html