Barney mentions that if a H-bomb hits New York, that everything to Philadelphia goes. Callahan, the cop, asked where does someone have to go (be be safe). Harris says Detroit. In a nuclear war, Detroit would also be a target because of the manufacturing in the area. In fact the government did a study showing where the "safe zone" is if a one megaton bomb hit Detroit.
Just after Wojo hangs up on his call with Callahan and Barney is looking for bulbs, there is a shadow of a boom mike or camera over Barney's head. Then there is an abrupt edit as Jilly enters.