My experience after declining the Hiroshima suicide photo mission is that I just don't get the reknown for completing it (worth the points "sacrificed" if my boat isn't lying on the bottom of Hiroshima Bay
)... Subsequent mission assignment has not been affected (stock V1.5 CD version)
BUT... IIRC, the declined photo missions came up during the mission and were not the first assignment out of the box.
Perhaps the experten on the forum can shed more light on the issue.