What's the word for constructing a false account...

[LoungeLizard]

...in the following circumstances.

For example: someone (who believes that aliens visit the earth) climbs up a mountain on their own and sees something that they wrongly interpret as an alien / UFO.

That person comes down the mountain and describes their encounter to a journalist.

This next bit is the point of my question: When describing the whole trip up & down the mountain, the person re-interprets lots of other trivial events & sights such that they support the 'alien encounter' story.

For example; they remember that they saw some sheep running down the mountain and claim that 'the sheep were running away from the alien'; whereas the sheep had just been startled by the person themself.  Another example; they remember some slightly unusual weather conditions or lights in the sky; both are random natural / man-made phenomena but the person builds them into the alien encounter theory.

The word or phrase that I am looking for is the act of mis-interpreting true events to support a false previously-held belief.  

[kazza12345]

is it confabulation?

[LoungeLizard]

Thank you, kazza.

Good suggestion, but as I understand it, confabulation means the invention of circumstantial details surrounding past events.

What I am looking for is a term which means mis-interpreting true circumstantial details in order to confirm a deeply-held prejudice.

[Marsh]

Misconstruction?

[THECORBYLOON]

What about "false premise?"