This was brought home to me when reading "von Braun, dreamer of space engineer of war" by Michael Neufeld.
In the biography he cowrote long after von Braun's death, Stuhlinger claims that von Braun went to an SS guard in the Mittelwek to criticise the mistreatment and crudely threatened with being put in a striped uniform too; later von Braun allegedly went to a higher SS officer and complained that the prisoners' bad health conditions contributed to poor workmanship in manufacturing. The problem is that Stuhlinger attributes an identical encounter with a guard to Auther Rudolph, whose Nazi enthusiasm is in little doubt, and both von Braun stories are told decades after the fact solely from memory of conversations with him, and in the context of defending him against charges of complicity in the horrors of Dora. As historical evidence, these uncorroborated, second hand anecdotes are highly dubious, although they cannot be ruled out as impossible. (p163)What I think is interesting is the compared to the Gospels how time can change how people view events. For example the earliest Gospel Mark from the wikipedia ::
Most critical scholars believe that Mark was written around or shortly after the fall of Jerusalem and the destruction of the Second Temple in year 70.70 years is a lot of time to blur what actually happened. It is the equivalent of myself writing about the second world war. The above example of von Braun you can see how flakey these accounts are writen 30 years after the events.
So what does this mean? Well I think the gospel stories are true; but it means the quest for the historical Jesus is more difficult.