I still find it hard to believe that he entirely made up the story about discovering the Gemini film canisters under the floor.
This a great story to analyze just on the face of it, never mind evidence or the changing details or the un-named other people involved. What is the actual story saying? At it's heart, it's a hero quest, or in Western Christan terms, a testimony or conversion story. Let's break it down:
1. The hero and the troupe.
It starts with our hero finding the film cans. Finding a lost or secret treasure or knowledge is a standard plot device used all the time. The discovery will start our hero on his path to conversion. It's a troupe. And where does he find the treasure, in storage room or locker? No, he has to rip up the carpet and go down in the crawl space of the building. This is Gilgamesh or Aeneous going into the underworld. Our hero has to go into the bowels of the JPL to discover the secret treasure. After finding it though, he's not too sure what he has, but that's ok because now comes:
2. The Oracle and the Grimoire.
Our hero learns about the significance of the treasure (film) from the Oracle, the keeper of secret wisdom. In this case, it's the coworker/friend that's into UFOlogy. And he has a Grimoire to help understand the treasure, that is, a notebook that apparently lists all the films taken from the Gemini spacecrafts and where to find pictures of UFOs on the films according to UFO lore. He's the keeper of secrets and the ancient written wisdom the explains the treasure. And what is revealed? The need to quest on:
3. The Conversion and Quest:
Turns out the treasure creates more questions than answers. The frames mentioned in the notebook have been removed. The treasure is incomplete, evil forces (government) have conspired to hide the truth and even this incomplete treasure is too valuable and has to be confiscated and once again hidden away. Yet, these hidden truths reveal the greater truth. There is yet more secret knowledge to obtain. Our hero is now converted, in modern speech he has swallowed the Red pill. He now moves on like Sir Galahad searching for the Grail and spreading the gospel of UFOlogy.
On a side note, it's full of other clever devices to make it nearly unfalsifiable and timeless. The sceptic is asked to prove a negative. We can show that, according to historical records is very unlikely that there would have been Gemini films at JPL, but it can't be proven. We can probably find all the photos taken by the Gemini crafts archived somewhere, but he has already said the evidence is missing.
He never actually saw any UFO pictures, therefore he's not locked into any particular UFO/alien zeitgeist. Had he said he saw pictures of flying saucers with little green men back then and now we know the aliens are grey and travel in tic-tacs, it would have dated his story. But he didn't see anything, so what he did not see can be applied to any scenario.