Imagine how the public would have reacted to a similar picture by a US journalist of a Nazi or Japanese sniper about to shoot US troops. Even in Viet Nam, Jane Fonda was just sitting on the anti-aircraft gun and wasn't actuallly shooting at US planes and the photo was taken by the North Vietnamese. The journalist should be held for war crimes.
Imagine if there had been a Times photographer "hanging" with Lee Harvey Oswald up in the Texas Book Depository. Would such a photo have led to a Pulitzer prize or an indictment for aiding and abetting an assasination?