The Jesus-appearance to Cleopas (& his Emmaus escort) reported in Lk 24 was no one’s invention (meaning it was no lie, nor literary creation, nor legend of Luke’s or Luke’s sources)..
We can debate these 3 arguments:
This is relevant if, given it also didn’t originate by accident, the only option left is that it originated as an honest eyewitness recounting. And of course an honest recounting could’ve only realistically originated with Cleopas and/or his companion reciting what they remember. (Rather than Cleopas’s companion, it was likely Cleopas himself that was Luke’s source. After all Luke was a Greco-Roman biography, and these conventionally cite witness sources via special inclusion of their names in the reported episode.)
In general, the author of Luke inherited his Jesus-biography from relevant witnesses.
A full page will debate these 5 arguments:
This is relevant because it suggests that in this specific case, Luke again is relaying relevant witness testimony: that of Cleopas and his companion.
In AD 30, the Jerusalem church was saying, “Jesus appeared to Cleopas and his companion.”
A full page will debate this piece of evidence:
But so what? Plausibly...
Shortly after Jesus’s crucifixion, a variety of different persons/groups began to testify that Jesus appeared to them alive from the dead.
This page covers these 7 examples: