I think it’s stretching things to be offended about the B-52 site. It’s a memorial to remember what happened. I watched the episode of Amazing Race and no where were there people cheering or celebrating that Americans were killed, it’s just there to remember what happened.
What surprises me more is that people were offended at this and not when all the contestants had to listen to the singing of Vietnam’s national anthem over and over again. Of course, while we watching the TV got subtitles, I’m guessing the contestants had no idea what the Vietnamese were saying (mostly socialist propaganda).
EDIT: I said that wrong above, it WASN’T the national anthem being sung, just a patriotic Vietnamese song. Couldn’t find the lyrics for it.