There's a book called "Where they lay" about the teams that go into SE Asia to recover remains. They never run out of volunteers. One of the stories was that a Huey crew had perished in a crash in the middle of an intense battle in a mountainous area of Vietnam. After the battle, what was accessible of the crew was bagged up and removed in haste and the wreck left there. When the CILHI team got there in the 90s, the site was overgrown so they had to clear it in tropical heat by hand. In time, they began to find scorched bits of the Huey and bone fragments, bits of clothing and so on. When they began to examine the bones, they soon established that they had found a fifth human, of American origin. It turned out that the Huey had crashed right onto the crash site of a previous helicopter and the fifth man was one of the crew of the original wreck. Another unpleasant point was that, especially in Laos, locals were falsifying crash sites to keep the Americans in situ for longer. They found that some locals were burying old helmets, cartridges, weapons, bits of clothing and even bones to try and convince the Yanks that they had found a previously unknown crash site. The dubious sites were soon identified as such but it soured relations with the Laotian Govt.