Reading the testimony from the Winter Soldier Investigation, it's obvious that the witnesses were extremely careful *not* to allege anything that could easily be verified or disproven. There are virtually no instances where names, dates and locations are available on these supposed atrocities.
It seems unlikely that this could have been an accident.
These "witnesses" made themselves scarce when the investigation was conducted, and would not provide details.
But strangely, all those horrific accounts of rape, torture, arson and slaughter that the VVAW had recorded in Detroit seemed to evaporate once the real investigation demanded by Senator Hatfield began. As recounted in Guenter Lewy's 1978 book “America in Vietnam,” few witnesses agreed to talk with military investigators, even after being assured that they would not be asked about their own crimes. Many of those who did permit interviews turned out never to have been in combat. Some of the most gruesome claims came from men who were imposters using the names of real Vietnam veterans. One Marine who had been in combat eventually told investigators that a member of the Nation of Islam had helped prepare his statement, and admitted that he had never witnessed any of the atrocities he had testified to in Detroit. In the end, the Navy was unable to verify any of the hundreds of war crimes alleged by the Winter Soldier Investigation. Neither has anyone else during the 33 years since, including journalists, historians, and military and Congressional investigators.