LBJ got probably the most undeserved Silver Star in history (for being a passenger on a bomber for all of 8 minutes of combat).
And that trumps a DFC, but it wasn't even 8 minutes of combat. No wonder JJ said it was surprising. I could see Johnson getting an Air Medal for his little joyride, but even if his aircraft hadn't had to turn back for mechanical reasons, there is no way what he did was Silver Star worthy or even DFC worthy.
It was surprising, because of the limited involvement LBJ had in the action. He was there on a fact finding mission, and not a direct combatant.
In most of Johnson's official photographs as president, he can be seen wearing the Silver Star lapel pin.
http://en.wikipedia.org/wiki/Lyndon_B._JohnsonJFK's Navy and Marine Corps Medal, while rarely awarded and marks heroism that, if in combat, is worthy of the Medal of Honor, is not considered a valor award and is considered lower ranking than the Silver Star.