There are many small details in the gospels which are either the hallmarks of authentic eyewitness accounts, or are invented to make the stories more convincing.
C.S. Lewis in his 1950 essay, "What are we to make of Jesus Christ?" wrote,
"the art of inventing little irrelevant details to make an imaginary scene more convincing is a purely modern art." He says, "There is nothing [like the fourth gospel], even in modern literature, until about a hundred years ago when the realistic novel came into existence."
http://merecslewis.blogspot.co.uk/2014/04/what-are-we-to-make-of-resurrection-of.html
I thought I'd check to see if this is correct. Can anyone refute Lewis' statement?
Just come across some interesting examples from a talk by Cold Case Christianity author, J Warner Wallace on YouTube.
First are the gospel accounts of the feeding of the 5,000. Matthew and Mark do not tell us where this took place, exactly. John says it was on the far side of the Sea of Galilee. Only Luke tells us that it was at a town called Bethsaida (Lk 9:10).
John gives us another detail: Jesus asks Philip where they can go to buy bread for the people (Jn 6:5). John has already told us that Philip was from the town of Bethsaida (Jn 1:44). But without Luke's additional information about the location, we wouldn't know why it made sense for Jesus to ask Philip in particular this question. Philip would know where they could go for food.
Second is the accounts of the soldiers beating Jesus. Matthew and Luke tell us that during the trial at the high priest's house, Jesus was asked to prophesy who it was had hit him:
Matthew 26:67-68 Then they spit in his face and struck him with their fists. 68Others slapped him and said, “Prophesy to us, Messiah. Who hit you?”
Luke 22:63-65 The men who were guarding Jesus began mocking and beating him. 64They blindfolded him and demanded, “Prophesy! Who hit you?” 65And they said many other insulting things to him.
Only Luke explains that they had blindfolded Jesus, hence the demand to prophesy which of them had hit him. He and Matthew use different words to describe the beating, the only phrase they share in common being "prophesy...who hit you". So apparently they used independent eyewitnesses.
That one version doesn't make sense without the other is characteristic of real eyewitness accounts, in which one confusing statement is frequently clarified by another witness, according to Wallace, himself a detective.